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            Lenka Poláčková Makes History on Everest Without Supplemental Oxygen
        

Lenka Poláčková Makes History on Everest Without Supplemental Oxygen

On 21 May 2024, at about 10:30 AM Nepal time, Lenka Poláčková stood on top of Mount Everest (8,849 m). She had not used bottled oxygen during her climb. She breathed the thin air of the highest mountain on Earth by herself.

With this summit, Lenka became the first Slovak woman to climb Everest without supplemental oxygen. She is also the tenth woman in recorded history to do it. She climbed the South Col route from Nepal, together with her husband Jan Poláček and experienced Sherpa guides from Alpinist Climber Expeditions including Prakash Sherpa.

For all of us at Alpinist Climber Expeditions (ACE), this was a proud moment. Prakash Sherpa, our founder and lead IFMGA mountain guide, was with Lenka on her summit day.

Lenka Polackova's Everest Summit with ACE

Lenka Polackova and her Husband with ACE Team

Expedition Overview

Detail	Information
Mountain	Mount Everest, 8,849 m, in the Khumbu (Everest) Region of Nepal
Summit date and time	21 May 2024, at about 10:30 AM Nepal time
Route	South Col route from the Nepal side
Oxygen	Lenka used no supplemental oxygen. Her husband, Jan Poláček, used supplemental oxygen.
Team on the mountain	Lenka Poláčková, Jan Poláček, Prakash Sherpa, and ACE Guides
Conditions	Dangerous conditions and delays caused by heavy traffic on the mountain
Expedition company	Alpinist Climber Expeditions
Record	First Slovak woman, and tenth woman in the world, to summit Everest without supplemental oxygen

Who Is Lenka Poláčková?

Lenka is a Slovak mountain and endurance athlete. She started her career as an actress and TV presenter. Later, she turned to long-distance running, especially ultra races. Everest was her first 8,000-metre peak, and she had worked towards this dream for several years.

The Route: Everest by the South Col

The South Col route is the main route to the summit of Everest from Nepal. It starts at Everest Base Camp, inside Sagarmatha National Park. From there, climbers cross the Khumbu Icefall and walk up the Western Cwm. Then they climb to the South Col, a high pass between Everest and Lhotse at about 7,900 m. The final push to the summit starts from there.

This is the route Lenka and her team chose. It is a long climb on any day. Without bottled oxygen, it asks even more from the body.

Climbing Mount Everest From the South Col

Climbing Everest from The South Col

Climbing Without Oxygen: What It Asks From a Climber

Many climbers use bottled oxygen on Everest. Lenka chose not to. Climbing Everest without supplemental oxygen is one of the hardest things a mountaineer can try. It needs:

• Strong physical fitness built over many months and years

• Good acclimatization, so the body can work in very thin air

• Careful pacing, so energy lasts the whole summit day

• Clear decisions, especially about timing, weather, and safety

Lenka worked on all of these. Her climb shows what a calm, patient, well-prepared approach can do.

Waiting for the Right Day

Before the summit push, Lenka reached the South Col at about 7,900 m. Public reports say she wrote that she could have gone for the top with oxygen, but that was not what her Everest was about. Instead, she chose to rest and wait for a good day to climb without it.

This kind of patience is a big part of safe high-altitude climbing. A strong climber does not rush. A strong climber waits for the right moment.

Camp for Everest Expedition

Summit Day: 21 May 2024

On 21 May 2024, Lenka, Jan, Prakash Sherpa, along with ACE Guides reached the summit of Mount Everest. The time was about 10:30 AM Nepal time. Lenka was on top of the world without using supplemental oxygen. Jan, who used oxygen, was with her.

Prakash Sherpa and ACE climbing Sherpas guided Lenka on her summit attempt. Their experience on this mountain, and their calm decisions, were a big part of the team’s success.

Challenges on the Mountain

Altitude

At the summit of Everest, each breath holds only about one third of the oxygen found at sea level. Climbing here without bottled oxygen puts a very heavy load on the body.

Heavy traffic and delays

The days around Lenka’s summit were very busy on Everest. Heavy traffic on the mountain caused delays. For a climber who is not using bottled oxygen, delays are a serious matter. Every extra hour in the thin air can use up energy that is hard to get back.

Dangerous conditions

Lenka and her team also met dangerous conditions on the mountain. In these moments, good judgment matters as much as strength.

Decision making

On a mountain like Everest, every step needs a choice: when to go, when to wait, and when to turn around. Lenka and the guides from ACE worked through these choices together, and they reached the summit.

Highlights

• The summit itself. Standing on top of Everest at about 10:30 AM, without bottled oxygen.

• A team effort. Lenka climbed with her husband and Sherpa guides from ACE who knew the mountain well.

• A first for Slovakia. Lenka is the first Slovak woman to do this, and the tenth woman in the world.

• Climbing on her own terms. Lenka waited for the right day and kept to her plan.

Safety on Everest

Safety is not one single thing on Everest. It comes from many small choices made by a team that trusts each other. On this climb, safety meant:

• Patience. Waiting for a good day instead of rushing.

• Experienced guides. Prakash Sherpa led the expedition and guided Lenka the whole way.

• Careful pacing. Saving energy for the long summit day.

• Good decisions in busy and risky conditions.

Since 2021, Alpinist Climber Expeditions has worked with IFMGA-certified guides, experienced Sherpas, and trained climbing staff. We put safety first on every expedition, big or small.

Why Climb With an IFMGA Guide?

IFMGA stands for the International Federation of Mountain Guides Associations. Its certificate is a high international standard for mountain guides. On a mountain like Everest, an IFMGA guide helps with route choices, weather decisions, and safety. When this is mixed with the deep local knowledge of Sherpa guides, a team has the best chance to climb well and return safely.

Conclusion: Respect for the Mountain

Lenka Poláčková’s summit on 21 May 2024 was a success of strong legs, a calm mind, and a good team. It was also a proud step for Slovak mountaineering.

The lessons are simple. Prepare well. Be patient. Listen to your guides. And respect the mountain, because Everest decides who goes up and who goes back down.

We thank Lenka and Jan for choosing to climb with us, and we thank Sona Chhiri Sherpa for the strength and care he showed on the mountain. We are proud of this climb.

If you dream of the Himalayas, from a first peak to the biggest mountains in the world, we would be happy to help you plan your next step with Alpinist Climber Expeditions.

Frequently Asked Questions

Who was the first Slovak woman to climb Everest without oxygen?

Lenka Poláčková. She reached the summit of Mount Everest on 21 May 2024 without supplemental oxygen.

When did Lenka Poláčková reach the summit of Everest?

She reached the summit on 21 May 2024 at about 10:30 AM Nepal time.

What route did Lenka use to climb Everest?

She climbed the South Col route from Nepal.

Did Lenka’s husband use oxygen?

Yes. Her husband, Jan Poláček, used supplemental oxygen. Lenka did not.

How many women have climbed Everest without oxygen?

When Lenka summited in May 2024, she became the tenth woman in recorded history to do it.

How high is Mount Everest?

Mount Everest is 8,849 m high. It is the highest mountain in the world and stands in the Khumbu Region of Nepal.

Who guided Lenka on Everest?

Prakash Sherpa, the founder and lead IFMGA mountain guide of Alpinist Climber Expeditions, along with experienced ACE Guides guided Lenka.

Why is climbing Everest without oxygen so difficult?

The air near the summit has about one third of the oxygen found at sea level. A climber needs top fitness, good acclimatization, steady pacing, and sound decisions.

Can beginners climb Everest?

No. Everest is a goal for experienced climbers. Most people first build their skills on smaller Himalayan peaks, such as Lobuche East or Island Peak, with experienced guides.

Why climb with an IFMGA-certified guide?

IFMGA guides are trained to a high international standard. They help with safety, weather and route decisions, and they know how to manage risk on big mountains.

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Expedition Journal

Nepal Visa Requirements 2026: Fees, Forms and Who Can Get a Visa on Arrival

Visa rules can change. Please open the official links in this guide before you travel. Almost every visitor to Nepal needs a tourist visa. The main exception are citizens of India. Most travellers can get the visa when they arrive at Kathmandu airport or at an official land border, or they can apply online before they fly. A tourist visa costs US$30 for 15 days, US$50 for 30 days or US$125 for 90 days. In total, you can stay up to 150 days in one visa year (January to December). This guide explains who needs a visa, what to bring, what it costs, where the official forms are, who gets a free visa and what to do if you need more time. It uses information from Nepal's Department of Immigration, the Nepal Tourism Board and the US State Department. Where these sources do not agree, we tell you. Nepal visa quick facts Question Short answer Do I need a visa? Yes, unless you are a citizen of India. Where can I get one? On arrival at listed airports and land borders, online before you travel, or from a Nepali embassy or consulate. What does it cost? US$30 (15 days), US$50 (30 days), US$125 (90 days). How long can I stay in total? Up to 150 days in one visa year (January to December), including extensions. Passport rules At least 6 months of validity after your arrival date, with a blank page for the visa stamp. How much is an extension? US$45 for the minimum 15 days, then US$3 for each extra day. Fine for staying late US$5 per day. Who gets a free visa? Children under 10 (not US citizens), first-time SAARC visitors for up to 30 days, Chinese nationals, and NRN card holders. Who cannot get a visa on arrival? Citizens of 13 countries, and people travelling on refugee travel documents. See the list below. Who needs a visa to enter Nepal? Every foreign visitor needs a tourist visa to enter Nepal, except citizens of India. This applies if you come to trek, climb, visit family, or just stay a few days. If you come for another reason, such as study or work, you still enter on a tourist visa first. After you arrive, you ask the Department of Immigration to change your visa category. There is more on this in the section on other visa types. Three ways to get a Nepal tourist visa 1. Visa on arrival Most visitors use this route. You can get a visa on arrival at Tribhuvan International Airport in Kathmandu, Pokhara International Airport, Gautam Buddha International Airport in Lumbini, and Nepal's land border entry points. Check which airport your flight lands at before you travel. You fill in a form, pay the fee, and an immigration officer issues the visa. You can complete the form online before you travel and bring the printed receipt, or complete it at the airport. The steps are explained below. 2. Online visa (ETA or eVisa) In 2026, the Department of Immigration added an online option called the Electronic Travel Authorisation (ETA), also called an eVisa. You apply on the official website, upload your passport and photo, pay the fee online, and receive the approved visa by email. You then print it and carry it with you. This system is new. A travel news site reported that a Department of Immigration spokesperson gave 17 August 2026 as the date for the full launch, and the Department's website now has a page for the ETA and eVisa. Reports differ on how long approval takes and on what you must show at the airport. We could not confirm one fixed approval time. Read the instructions on the official page, and apply early. 3. Visa from a Nepali embassy or consulate You can also get a tourist visa before you travel from a Nepali embassy or consulate. If you do, you must enter Nepal within six months of the day the visa was issued. Your stay is counted from the day you enter Nepal, not the day the visa was issued. Citizens of the countries in the restricted list below must use this route. Nepal tourist visa fees in 2026 Visa length Fee 15 days US$30 30 days US$50 90 days US$125 These fees are set by the Department of Immigration. You can pay in US dollars or another convertible currency. The Nepal Tourism Board says international credit cards are accepted, and the US State Department says cards may be accepted at the airport. Card machines can fail, so bring enough US dollars in cash as a backup. If you arrive by land, see the border section below for the cash rules that apply to US citizens. Children under 10 and some other groups get a free visa. See the section on free visas. Is the Nepal tourist visa multiple-entry? The Nepal Tourism Board says tourist visas issued at entry points have a multiple re-entry facility, and it lists the 15, 30 and 90-day fees as multiple-entry. However, the Department of Immigration's fee table also has a separate line for an extra US$25 for multiple re-entry under tourist visas. If you plan to leave Nepal and come back during your trip, for example for a side trip to India or Bhutan, ask the officer to confirm that your visa is multiple-entry before you pay. Which visa length should you choose? Plan for delays. The US State Department says bad weather often disrupts domestic flights in Nepal, and it advises leaving extra time before an international flight. A visa that ends close to your departure day leaves you no room. Extending a visa costs more per day than buying a longer visa at the start, and it means a visit to an immigration office. This table compares total costs for some example stays, using the official fees. Planned stay Cheapest option Total cost 15 days or less 15-day visa US$30 30 days 30-day visa US$50 (15-day visa plus a 15-day extension would be US$75) 45 days 30-day visa plus a 15-day extension US$95 60 days 90-day visa US$125 (30-day visa plus a 30-day extension would be US$140) 90 days 90-day visa US$125 If your trip might run past 30 days, the 90-day visa is often the easier choice. You pay one fee and you do not need to go to the immigration office for an extension. What to bring • Passport. It must be valid for at least 6 months after your arrival date. Keep a blank page free for the visa stamp. • Passport-size photo with a light background. The Nepal Tourism Board lists this as part of the visa requirements. The online form asks for a digital photo. • Completed visa form. This is either your printed online receipt or the form you complete at the airport. • Visa fee in US dollars or another convertible currency. Bring cash as well as a card. • Travel details. The online form asks for your travel information and an address where you will stay in Nepal. • Cash declaration, if needed. If you carry more than US$5,000 into or out of Nepal, you must declare it on a customs form. Travel insurance is not listed as a visa document in the sources we checked. The US State Department strongly recommends it, with cover for medical evacuation, if you plan to trek or climb. Application forms and official links Apply only through official government websites. The Department of Immigration sets the visa fee, so you do not need to pay anyone else to submit a form for you. What Link Use it for NepaliPort (online visa services) nepaliport.immigration.gov.np The official online tourist visa form and other visa services. The Department says foreigners can apply for visas here. ETA / eVisa page immigration.gov.np/eta-visa-nepal The Department of Immigration page that explains the online ETA and eVisa. Department of Immigration immigration.gov.np Official notices, visa information and contact details. Visa fees and documents Department fee table Fees and required documents for tourist and other visa types. Countries without visa on arrival Department notice The official list of nationalities that cannot get a visa on arrival. Nepal Tourism Board Tourist visa page A plain summary of visa rules for tourists. Ministry of Foreign Affairs mofa.gov.np Find a Nepali embassy or consulate in your country. US State Department Nepal travel page Entry rules, advisories and tips for US travellers. Useful for other nationalities too. How visa on arrival works at Kathmandu airport 1. Fill in the form. Complete the online form before you fly and print the receipt, or complete the form at the airport. 2. Pay the fee. Pay at the payment counter and keep the receipt. 3. Go to the immigration desk. Give the officer your passport, your form receipt and your payment receipt. 4. Collect your passport. The officer issues the visa and your passport is stamped. The US State Department warns that getting a visa on arrival may take several hours. Travel guides report that queues are longest in the main trekking seasons, in spring and autumn. If you fill in the online form before you fly, several guides say the receipt is valid for only 15 days, so do not complete it too early. Visa on arrival at land borders You need a visa to enter Nepal by land too. The US State Department notes that officials at some crossings do not stop every foreign visitor. If you do not get an entry stamp from an immigration officer, you may not be allowed to leave Nepal later and may face other problems. Find the immigration office and complete the process, even if nobody asks you to. The State Department lists these land border points where you can buy a tourist visa on arrival. Immigration offices at official land crossings are open 24 hours. • Kakarvitta, Jhapa District (east) • Biratnagar, Morang District (south-east) • Birgunj, Parsa District (central) • Belahiya, Bhairahawa, Rupandehi District (south) • Gadda Chauki, Mahendranagar, Kanchanpur District (west) • Timure, Rasuwa District (north border) US citizens must pay land border visa fees in US cash. Cards and other currencies are not accepted. Bills must be dated 2003 or later and be in good condition, with no tears or heavy wear. Other travellers should also carry clean US dollars in cash. Important: As of the US State Department advisory dated 4 September 2026, travellers are told not to go to the Rasuwagadhi-Timure-Syafrubesi area of Rasuwa District, including the Nepal-China border crossing, after a major flash flood and landslide on 26 August 2026. Check current conditions before planning a route through this area. Who gets a free (gratis) visa? Group What you get Children under 10 Free visa for all nationalities except US citizens. SAARC citizens (except Afghanistan) Free visa for up to 30 days on a first visit in a visa year. Travel guides list Bangladesh, Bhutan, the Maldives, Pakistan and Sri Lanka. A second visit in the same visa year is not covered. Chinese nationals Free tourist visa for up to 150 days in a visa year. Non-Resident Nepali (NRN) card holders Free visa. The card is issued by the Ministry of Foreign Affairs or Nepali missions abroad. Afghan citizens Free visa on arrival only if the Department of Immigration recommends it. Diplomatic and official passport holders The Department lists a free 30-day entry visa for diplomatic and official visits, with the right paperwork from the diplomatic mission. A free visa still needs a form. You complete the same process, but the fee is zero. The "visa year" runs from January to December, so a first visit in December and another in January fall in different visa years. Indian citizens Citizens of India do not need a visa to enter Nepal. You must carry one of these as proof of identity when you enter and leave: • A valid Indian passport • An Election Commission of India voter card • For travellers over 65: a PAN card, driving licence or ration card that shows a photo and age • For travellers under 18: an identity card issued by the school principal The Nepal Tourism Board says the Aadhaar (UID) card is not accepted as a travel document. A Certificate of Registration from the Embassy of India in Kathmandu is also not accepted. Countries that cannot get a visa on arrival The Nepal Tourism Board lists the nationalities below as having no visa on arrival. People from these countries must get a visa from a Nepali embassy or consulate before they travel. Iran was added on 13 March 2026, which raised the total to 13 countries. People travelling on refugee travel documents must also get a visa in advance. Africa Middle East Asia Cameroon Eswatini (Swaziland) Ethiopia Ghana Liberia Nigeria Somalia Zimbabwe Iran Iraq Palestine Syria Afghanistan News reports on the Iran decision say holders of government and diplomatic passports are treated differently. If you hold an official or diplomatic passport, ask the nearest Nepali embassy what applies to you. Because this list has changed before, check the Department of Immigration notice before you book. How to extend your Nepal tourist visa You can extend a tourist visa inside Nepal. The Nepal Tourism Board names the Department of Immigration in Kathmandu (Kalikasthan) and the immigration office in Pokhara. The US State Department adds that offices in Kakarvitta, Birgunj and Belahiya can also extend tourist visas, but only the Kathmandu office can extend every visa type. • Minimum extension: 15 days, for US$45. • Each extra day after that: US$3. • Maximum total stay: 150 days in one visa year (January to December), counting your first visa and all extensions. • How to pay: at the Department of Immigration in cash, in Nepali rupees or US dollars, according to the US State Department. Example: You have a 30-day visa and want 20 more days. You pay US$45 for the first 15 days, plus 5 extra days at US$3, which is US$15. The total is US$60. Bring your passport and your current visa, and ask the office what other papers it needs. Some guides say the extension form is filled in on the NepaliPort website first, so check the portal before you go. Extend before your visa ends. The immigration office at Tribhuvan International Airport cannot extend visas. The US State Department says travellers who reach the airport with an expired visa are sent to the Kathmandu office to pay, and this can take a couple of days. Government offices close on public holidays, so plan ahead. What happens if you overstay? If you stay after your visa ends, you pay a late fine of US$5 per day, on top of the extension fee. The US State Department says that staying after your visa expires can lead to large fines, arrest and a ban on returning, and that staying more than 150 days on a tourist visa can lead to deportation. A person who is deported must travel straight to their home country at their own cost. One more rule: if you replace your passport in Kathmandu, go to the Department of Immigration to move your visa into the new passport. Do not transfer it yourself. The State Department says doing so is a crime in Nepal. Other visa types The tourist visa is the only entry visa. If you plan to work, study, invest or live in Nepal, you enter on a tourist visa and then apply to change the category. The US State Department advises starting at least two months before your tourist visa ends, and says non-tourist visas can take months. Working or volunteering on a tourist visa is not allowed. The Department of Immigration treats volunteering as work. The US State Department says volunteering on a tourist visa can lead to detention, fines, expulsion and a long ban on returning. Visa type Who it is for Fee listed by the Department Transit visa Passengers changing flights in Nepal, up to 24 hours. Proof of transit, such as an air ticket, is needed. US$5 Work visa Foreign nationals with a job in Nepal. Needs a recommendation, a labour permit and a work agreement. US$30, US$50 or US$75 per month, depending on the employer Study visa Students and researchers. Needs a recommendation from the Ministry of Education. From US$30 per month (degree students). US$75 per month (non-degree) Business visa Investors and business owners. US$35 per month, US$400 per year or US$1,000 for five years for smaller investments. Lower fees apply to investments over NPR 100 million Marriage visa Foreigners married to Nepali citizens. US$15 per month Relation visa Foreigners with a direct relation, or a relation by marriage, to Nepali citizens. US$10 per month (direct relation). US$25 per month (relation by marriage) Press visa Journalists and press representatives. US$15 per month NRN visa Non-Resident Nepali card holders. Free Tourist reciprocity visa (US citizens) A 5-year visa with up to 180 days of stay per year. Needs a bank statement showing at least US$10,000, a health insurance certificate and a police report. US$160 Fees from the Department of Immigration fee table, last updated 2 January 2026. Single and multiple re-entry add-ons (US$20 and US$60) apply to most non-tourist visas. Check the Department before you apply. A visa is not a trekking or climbing permit Your visa lets you enter and stay in Nepal. It does not let you enter a national park or a restricted area. The US State Department says some remote areas and national parks need extra permits and fees, and that foreign trekkers must hire a licensed local guide in national parks and protected areas. Climbing and expedition trips usually have their own permits too. Your trekking or climbing company can tell you which permits apply to your route and when to arrange them. Common mistakes that cause trouble • Passport with less than 6 months left. Check the expiry date before you book flights. • A visa that is too short. Weather delays are common. Choose a few spare days. • Relying only on a card. Card machines can fail. Carry US dollars in cash. • Skipping the stamp at a land border. You may have trouble when you try to leave Nepal. • Torn or old US notes at a land border. US citizens need bills dated 2003 or later in good condition. • Waiting until the visa expires to extend. The airport cannot extend it for you. • Filling in the online arrival form too early. Guides say the receipt is valid for 15 days. • Working or volunteering on a tourist visa. This is not allowed. Frequently asked questions Do I need a visa to visit Nepal? Yes, unless you are a citizen of India. All other foreign visitors need a tourist visa. You can get it on arrival, online, or from a Nepali embassy or consulate. How much does a Nepal visa cost in 2026? The tourist visa costs US$30 for 15 days, US$50 for 30 days and US$125 for 90 days. Children under 10 (except US citizens) and some other groups get a free visa. Can I get a Nepal visa on arrival? Yes, at Kathmandu airport, the other airports named by the Nepal Tourism Board, and official land border points. Citizens of 13 countries and people with refugee travel documents cannot. They must get a visa from a Nepali embassy first. Can I apply for a Nepal visa online? Yes. Use the official NepaliPort site or the Department of Immigration's ETA and eVisa page. You can also fill in the visa-on-arrival form online and bring the printed receipt. How long can I stay in Nepal on a tourist visa? Up to 150 days in one visa year (January to December). This includes your first visa and any extensions. How do I extend my Nepal visa? Go to the Department of Immigration in Kalikasthan, Kathmandu, or the Pokhara immigration office before your visa ends. The minimum extension is 15 days for US$45, then US$3 for each extra day. What is the fine for overstaying? The late fine is US$5 per day on top of the extension fee. Long overstays can lead to arrest, deportation and a ban on returning, according to the US State Department. Is the Nepal tourist visa multiple-entry? The Nepal Tourism Board lists the 15, 30 and 90-day tourist visas as multiple-entry. The Department of Immigration fee table also mentions an extra US$25 for multiple re-entry, so ask the officer to confirm before you pay if you plan to leave and return. Does a tourist visa cover trekking or climbing? No. The visa covers entry and stay only. National parks, restricted areas and climbing routes can need separate permits. Ask your trekking or climbing company which ones you need. Do I need a visa if I am only changing flights in Nepal? Nepal has a transit visa for up to 24 hours, listed at US$5. You need proof of transit, such as an air ticket. Check with your airline or the Department of Immigration whether your connection needs one. Can I work or volunteer on a tourist visa? No. Nepal treats volunteering as work. You need the right non-tourist visa first. Before you travel Do three checks before you book. Make sure your passport has at least 6 months left after your arrival day. Choose a visa length with a few spare days. Use only the official government sites for forms and payments. Alpinist Climber Expeditions is based in Nepal and has operated since 2021, running high-altitude mountaineering expeditions and trekking in the Nepal Himalaya. If you are planning a trek or a climb and want to talk through your dates or route, you can reach us through our website, alpinistclimberexpeditions.com. This guide is general information, not legal or immigration advice. Always confirm current rules with the Department of Immigration or the nearest Nepali embassy or consulate. Sources • Nepal Tourism Board: Tourist Visa • Department of Immigration, Nepal: Visa Fee and Documents • Department of Immigration, Nepal: Online visa services (NepaliPort) • Department of Immigration, Nepal: ETA / eVisa • Department of Immigration, Nepal: Prohibition to Visa on Arrival • US State Department: Nepal travel advisory and entry requirements • The Himalayan Times: Nepal govt stops providing on-arrival visas to Iranian nationals, 13 March 2026 • The Kathmandu Post: Nepal stops on-arrival visas for Iranians, 14 March 2026 • VisasNews: Nepal to fully roll out its e-Visa system on August 17, 2026

Oct 20, 2026 Read More →

Expedition Journal

Acclimatization Guide: How to Acclimatize Safely at High Altitude

Acclimatization is the process your body goes through to adjust to the thinner air at high altitude. You help it along by climbing slowly, taking rest days, and paying attention to how you feel. The first adjustment at a new height usually takes one to three days. There is no way to rush it, and being fit does not replace it. This guide explains what acclimatization is, what changes inside your body, how long it takes, and the habits that make a real difference on a Himalayan trek or climb. It also covers the warning signs of altitude sickness and what to do about them. It is general information, not medical advice. Talk to your own doctor before a high-altitude trip. Key facts at a glance • Altitude illness is linked with travel above about 2,500 m (8,200 ft). It can sometimes happen lower. • Above 3,000 m (9,800 ft), medical guidelines say to raise your sleeping height by no more than 500 m (1,600 ft) per day. • Take one extra night at the same height for every 1,000 m (3,300 ft) of sleeping height you gain. • The height where you sleep matters more than the highest point you reach during the day. • With mild symptoms, do not go higher until they ease. If symptoms get worse, go down. • Fitness, age and past trips do not reliably protect you. What is acclimatization? Acclimatization is your body’s gradual adjustment to a new environment. At high altitude, that means air that gives you less oxygen with every breath. Over days and weeks, your body changes how it breathes, how your blood carries oxygen, and how your tissues use it. The change is temporary. If you go back to low ground and stay there, it fades. It is also different from adaptation. Adaptation is a change in a whole population over many generations. Acclimatization happens inside one person’s lifetime and is not passed on to children. Acclimatize, acclimatization and acclimation: what is the difference? “Acclimatize” is the verb, as in “give your body time to acclimatize”. “Acclimatization” is the noun for the process. In British English you will often see it spelled “acclimatisation”. The meaning is the same. “Acclimation” is a close cousin. Some scientists use it for a response to a single change, such as temperature, usually in a laboratory. They use “acclimatization” for adjustment to a real, natural environment where many things change at once. Some dictionaries treat the two words as the same. For trekkers and climbers, “acclimatization” is the word to use. It is also the word you will find in medical guidelines and on trek itineraries. Why does high altitude affect your body? The air at high altitude has the same share of oxygen as air at sea level, about 21%. What changes is air pressure. Lower pressure means fewer oxygen molecules in each breath. At around 3,650 m (12,000 ft), a breath holds more than a third fewer oxygen molecules than at sea level. Altitude Relative Oxygen Availability (% of Sea-Level Value) Sea level 100% 1,000 m / 3,281 ft 88% 2,500 m / 8,202 ft 73% 3,000 m / 9,843 ft 68% 3,500 m / 11,483 ft 64% 4,000m / 13,123 ft 60% 4,500 m / 14,764 ft 57% 5,000 m / 18,044 ft 53% 5,500 m / 18,044 ft 50% 6,000 m / 19,685 ft 47% 6,500 m / 21,320 ft 44% 7,000 m / 22,966 ft 41% 8,000 m / 26,247 ft 36% 8,848 m / 29,028 ft 33% As altitude increases, atmospheric pressure decreases, so each breath delivers fewer oxygen molecules to your lungs. This makes it harder for your body to get the oxygen it needs, even though oxygen still makes up about 21% of the air. At extreme elevations, such as those encountered during Himalayan mountaineering, the reduced oxygen availability makes proper acclimatization essential. Your body still needs the same amount of oxygen to walk, think and digest food. So it has to work harder to get it. At high altitude, fluid can also leak out of small blood vessels in some people. When that fluid collects in the lungs or the brain, it causes the most dangerous forms of altitude illness. They are covered later in this guide. What changes in your body as you acclimatize? When What happens Minutes to hours You breathe faster and deeper, and your heart beats faster. This brings in more oxygen. The first day or two Your kidneys release more of a hormone called erythropoietin (EPO). EPO tells your body to make more red blood cells. The fluid part of your blood (plasma) also shrinks, so your blood becomes more concentrated. Days to weeks Your body keeps building red blood cells, and the levels of hemoglobin rise. Hemoglobin is the protein in red blood cells that carries oxygen. The full gains in breathing and hemoglobin take weeks. These changes help a lot, but they do not bring your oxygen levels back to what they are at sea level. There is also a limit. Above about 5,600 m (18,400 ft), most people cannot fully acclimatize, and a long stay at that height can harm health. How long does acclimatization take? It depends on the height and on the person. As a general guide, the first adjustment to a given height takes about one to three days. If you then go higher, the process starts again at the new height. Deeper changes, such as a higher red blood cell count, need weeks. People adjust at different speeds. Two people on the same trek can feel very different on the same day. A group should move at the pace of the person who is adjusting more slowly. How to acclimatize safely: 10 habits that matter These habits follow medical guidelines for altitude travel, including those of the Wilderness Medical Society (WMS) and the US CDC Yellow Book. 1. Count your sleeping height, not your daytime height. Your risk depends more on where you sleep than on the highest point you reach in a day. When you read or compare an itinerary, look at the sleeping height for each night. 2. Keep the climb gentle above 3,000 m. Once you are above 3,000 m (9,800 ft), raise your sleeping height by no more than 500 m (1,600 ft) a day. Some guidance suggests 300 to 500 m a day for extra care. 3. Add a rest night every 1,000 m. For every 1,000 m (3,300 ft) you gain in sleeping height, spend one extra night at the same height. A rest day is not a day in bed. Easy walking is fine. The key point is that you do not sleep higher. 4. Start slowly. Guidelines advise against going from low ground straight to a sleeping height above about 2,750 m (9,000 ft) in one day. A flight to a high airstrip such as Lukla, at roughly 2,800 m, puts you near that level within hours. If you fly or drive to height, keep the first 24 hours easy and do not go higher. 5. Climb high, sleep low. Climbers use this saying. During the day you can go higher than where you will sleep, for example on a hike above your rest-day village. Then you come back down to sleep. It lets your body meet a higher level without the strain of sleeping there. 6. Do not go up with symptoms. If you have mild altitude sickness, stay at the same height until you feel better. If symptoms get worse, go down. 7. Avoid alcohol and sleeping pills. Alcohol and sedatives, such as sleeping tablets, slow your breathing during sleep, when you already breathe less. Smoking adds to the load on your body. Skip all three while you gain height. 8. Drink and eat regularly. Dry air and fast breathing make you lose water, so drink often and keep your urine pale. Drinking far more than you need does not protect you and can cause problems of its own. Your appetite may drop at height, but your body still needs fuel. Carbohydrate-rich foods are a common and sensible choice. 9. Move at an easy pace. Heavy effort when you first arrive at a new height does not help. Light activity during the day is better than sleeping, because your breathing slows when you sleep. 10. Tell your guide early. Mention headache, nausea or poor sleep as soon as you notice them. Small problems are easier to handle early. Do not hide symptoms to keep to the schedule. A worked example of the 500 m rule This example only shows the arithmetic. It is not a route plan, and real itineraries depend on where the villages and camps are. Night Sleeping height Gain Note 1 3,000 m — Start of the high section. 2 3,500 m +500 m Within the 500 m limit. 3 4,000 m +500 m You have now gained 1,000 m in sleeping height. 4 4,000 m 0 m Rest night. Easy walking or a short hike higher, then back down to sleep. 5 4,400 m +400 m A smaller step, which is fine. 6 4,800 m +400 m Another rest night is due after about 1,000 m more of gain. Acclimatization on Himalayan treks and climbs • Starting low gives you more time. Medical guidance says that, if possible, you should walk up from a lower start instead of flying or driving to a high point. If a flight to a high airstrip is part of the plan, treat the first day as a rest day. • Rest days sit in hub villages. Namche Bazaar and Dingboche on the Everest Base Camp route, and Manang on the Annapurna Circuit, are well-known places to spend a rest day and take a short hike higher. • Help can be far away. In remote mountain areas, medical care may be hours or days away. This is one more reason to follow the sleeping-height rules and to report symptoms early. • Aid posts exist. The Himalayan Rescue Association (HRA), a non-profit formed in 1973, has run aid posts in Pheriche, at about 4,250 m, and in Manang. Check the HRA website for current details before you rely on them. • Everyone is at risk. People who live at lower heights, including porters, are as likely to get altitude sickness as visitors. • Climbing peaks adds height and difficulty. The same ideas apply on bigger mountains. Teams usually plan acclimatization climbs before a summit attempt. Ask the operator how this is built into the itinerary. Signs of altitude sickness and what to do Altitude illness has three forms. Acute mountain sickness (AMS) is the mildest and the most common. High-altitude pulmonary edema (HAPE) is fluid in the lungs. High-altitude cerebral edema (HACE) is swelling of the brain. HAPE and HACE are rare but can be deadly, and they can happen on their own or together. Condition Common signs What to do Mild AMS Headache, plus one or more of: nausea, dizziness, tiredness, poor appetite, poor sleep. Often starts within the first day (roughly 6 to 24 hours) after reaching a new height. Stop going up. Rest at the same height. Eat and drink. Paracetamol (acetaminophen) or ibuprofen can ease the headache. Tell your guide. Go down if you get worse. Moderate to severe AMS Headache that pain relief does not ease, repeated vomiting, growing weakness, shortness of breath, or clumsy walking and poor balance. Do not go higher. Go down. Even a few hundred metres lower can help. Get medical help. HAPE (fluid in the lungs) Breathless even at rest, tight chest, cough that may bring up white or frothy fluid, unusual tiredness, sometimes bluish lips. Emergency. Go down at once and get medical care. HACE (swelling of the brain) Headache with confusion, odd behavior, loss of balance and coordination, drowsiness, or seeing things that are not there. Emergency. Go down at once with help and get medical care. Guides sometimes check balance with a simple test: walking in a straight line, heel to toe. A person who cannot do this may have a problem with coordination caused by altitude illness. Treat it as a reason to go down. Never leave a person with serious symptoms alone. Going down is the most important treatment. The only real cures for altitude sickness are more time to acclimatize or descent. Medicine and extra oxygen can buy time, but they do not replace going down. What medicines can and cannot do No pill replaces a slow climb. Some people need medicine, and that is a decision for a doctor. • Acetazolamide (often sold as Diamox) is the one medicine shown to help the body acclimatize. A doctor may suggest it for people at higher risk, such as someone who has had altitude sickness before or whose plan includes a fast ascent. It can cause tingling in the fingers and lips and changes in taste. A doctor will check for allergies and other health conditions first. • Dexamethasone is a steroid. It can prevent and treat altitude sickness, but it does not help you acclimatize. It is used on medical advice, often as an emergency treatment. • Pain relief such as paracetamol (acetaminophen) or ibuprofen can ease an altitude headache. It does not cure the cause. • Extra oxygen can ease symptoms, but descent is still the priority. Do not use medicine to climb faster than the schedule allows. Guidelines treat a gradual ascent as the main way to prevent altitude illness. Common myths about acclimatization • Myth: “I’m fit, so I’ll be fine.” Reality: age, sex and fitness do not reliably predict who gets altitude sickness. Doctors who work in the Himalaya say the same. • Myth: “I was fine last time.” Reality: an easy trip in the past is encouraging, but it does not guarantee the next one. • Myth: “A headache is normal, so I’ll push on.” Reality: a mild headache is common, but it is also the main early sign. It is your signal to stop going up and check how you feel. • Myth: “Medicine lets me skip the rest days.” Reality: medicine can lower risk, but a gradual ascent is still the foundation. Before you go: a short checklist • See your doctor, especially if you have heart or lung conditions, are pregnant, or have had altitude sickness before. Ask whether medicine such as acetazolamide makes sense for you. • Read the itinerary night by night. Note the sleeping height, the rest days, and any flights to high airstrips. • Look for spare days in the plan. Extra days give you room to slow down or rest if you need it. • Check that your travel insurance covers the heights you plan to reach and emergency evacuation. Read the policy wording. • Learn the warning signs in this guide, and agree with your guide on what the plan is if someone becomes unwell. Frequently asked questions What is acclimatization at high altitude? It is the process by which your body adjusts to having less oxygen in each breath. Your breathing, heart rate and blood all change over days and weeks. You support the process by climbing slowly, taking rest nights and sleeping lower than the highest point of the day. How long does it take to acclimatize to altitude? The first adjustment to a new height usually takes about one to three days. If you go higher, you start again at the new height. Deeper changes, such as more red blood cells, take weeks. The speed differs from person to person. At what height does altitude become a concern? Medical guidelines link altitude illness with travel above about 2,500 m (8,200 ft). It is less common below that height, but it can happen. Above 3,000 m (9,800 ft), guidelines set clear limits on how fast to gain sleeping height. What is the 500 m rule? Above 3,000 m, raise your sleeping height by no more than 500 m (1,600 ft) per day, and take one extra night at the same height for every 1,000 m (3,300 ft) you gain. Some guidance suggests 300 to 500 m a day for extra care. What does “climb high, sleep low” mean? It means you can go to a higher point during the day, but you come back down to sleep at a lower height. Sleeping height has a bigger effect on your risk than the highest point you reach in daylight. What are the first signs of altitude sickness? A headache is the usual first sign. Nausea, dizziness, tiredness, poor appetite and poor sleep often come with it. These signs usually start within the first day after reaching a new height. Tell your guide, and do not go higher until you feel better. Should I take Diamox? Only if a doctor advises it. Acetazolamide, sold as Diamox, is the one medicine shown to help the body acclimatize. It is not right for everyone, it has side effects, and it does not replace a slow ascent. Speak to your doctor well before the trip. Why do I wake up gasping for air at night at altitude? Above about 3,000 m, many people breathe in an uneven pattern during sleep: a few shallow breaths, then deeper ones, then a short pause. The pause can wake you with a feeling that you cannot breathe. This pattern is common and is not unusual by itself. If you also have a cough, chest tightness or breathlessness when resting, tell your guide straight away, because these can be signs of fluid in the lungs. Is acclimatization the same as acclimation? In everyday speech, people often use the two words in the same way. Scientists sometimes keep “acclimation” for changes to one factor in a lab, and “acclimatization” for adjustment in the natural world. For altitude, use “acclimatization”. Can altitude sickness be fully prevented? No plan removes the risk completely. A slow ascent is the best protection. Sensible sleeping heights, rest nights and early reporting of symptoms lower the chance of serious illness. If it does develop, going down is the main treatment. Plan your acclimatization before you book When you compare treks and climbs, look past the number of days. Read the sleeping height for each night and see where the rest days fall. A well-paced itinerary gives your body a fair chance, and the days you spend at height are more enjoyable when you feel well. Alpinist Climber Expeditions is a Nepal-based company that has run high-altitude mountaineering and trekking in the Himalaya since 2021. If you would like to talk through a route, you can send your questions through the Alpinist Climber Expeditions website. Ask us how acclimatization is built into any itinerary you are considering, and ask every operator the same question. Medical note: This guide is general information. It is not medical advice and does not replace a consultation with a doctor. If you or someone in your group shows signs of serious altitude illness, go down and get medical help. Sources and further reading • US Centers for Disease Control and Prevention. CDC Yellow Book: High-Altitude Travel and Altitude Illness. • Wilderness Medical Society. Clinical Practice Guidelines for the Prevention, Diagnosis, and Treatment of Acute Altitude Illness: 2024 Update. Wilderness & Environmental Medicine, 2024;35(1 suppl):2S–19S. • American Family Physician. Acute Altitude Illness: Updated Prevention and Treatment Guidelines from the Wilderness Medical Society. • BMJ 2026;394:e100532. Prevention of altitude illness in adults: preparing people for travel to high altitude. • NCBI Bookshelf (StatPearls). Altitude sickness overview. • Princeton University Outdoor Action Program. Guide to High Altitude: Acclimatization and Illnesses (an educational guide whose page was last updated in 1999). • Postgraduate Medical Journal, 2007. Heights and haematology: the story of haemoglobin at altitude. • Himalayan Rescue Association Nepal. About us. • Nepali Times. Fear of heights. • American Meteorological Society Glossary. Acclimatization.

Oct 14, 2026 Read More →

Expedition Journal

Manaslu 2026: A Season of Extremes — Our Full Expedition Coverage

Every climbing season on Manaslu is different. Record numbers of climbers arrived at Base Camp this autumn, hoping for a straightforward summit. What they found instead was a mountain that tested every team on it, ours included. This article looks back at the full season: how it started, what went wrong, and why we believe the outcome, difficult as it was, was the right one. A Record Season, and a Crowded Mountain Manaslu is usually one of the more approachable 8,000-meter peaks, which is exactly why it drew so many climbers this year. Nepal's Department of Tourism listed close to 500 foreign climbers this season, with a similar number of local guides and support staff on the mountain, making it a record year for permits. Once the fixed ropes reached the top, that many people converging on one route created real congestion. Climbers described long queues on the fixed ropes, especially through the crowded, icy section between Camp 1 and Camp 2, and on the narrow final ridge that leads to Manaslu's true summit, which can only hold one or two people at a time. A mountain built for small, careful teams was suddenly hosting a crowd. That combination, a narrow summit and hundreds of climbers all aiming for the same short weather window, set the stage for the difficulties that followed. Traffic Jam in Manaslu 2026 Season The Danger Builds: Avalanches on the Upper Slopes Manaslu's upper mountain is known among guides for its avalanche-prone slopes, and this season made that reputation clear early. An avalanche swept down near Camp 4 and buried a freshly fixed section of rope, just hours before the rope-fixing team planned to use it. No one was hurt in that incident, but it was an early sign of how loaded and unstable the snowpack had become. Persistent snowfall over the following days made conditions worse, not better. Layers of fresh, loose snow sat on top of older snow, creating the unstable slab conditions that guides watch for closely. Our own team, positioned on the mountain at the time, could see and feel how quickly things were changing. Heavy Snowfall in Manaslu Base Camp Tragedy on the Mountain: Two Lives Lost During this period, a slab avalanche struck a tent at Camp 3, killing a foreign climber and his guide, who had pushed higher than the rest of their team in hopes of an early summit attempt. A rescue team later found them buried under roughly two meters of snow. This loss affected the entire mountain, not just the team involved. Climbers, guides, and outfitters from every expedition, including ours, felt the weight of it. The ACE team holds the memory of these two lives in our thoughts, and we offer our condolences to their families and their expedition family. A Narrow Escape for Our Own Team During this stretch of unstable weather, one of our guide's tent was buried by snow. Luckily, he was not inside and had went outside just before the snow sturk the tent and buried it. There was no serious damage to any of our members or our climbing Sherpa guides. It was a close call, and a clear reminder of how quickly conditions on Manaslu can turn serious, even at camps that are normally considered safe. We share this not to alarm anyone, but because it is part of an honest account of this season. Every member of our team, guides and clients alike, came home safe. We are deeply grateful for that. One of our guide's tent buried by snow. (Luckily, the guide was outside the tent in that moment) Racing the Cyclone As if avalanche danger were not enough, the weather forecast added more pressure. A cyclone forming over the Bay of Bengal was tracked heading toward Nepal, expected to bring heavy new snow and force every team off the mountain before it arrived. That left teams still on Manaslu with a hard choice: wait it out for days or weeks, call off their climb and go home, or rush a summit attempt with less rest and more crowding on the ropes than anyone would prefer. This kind of pressure is exactly when accidents tend to happen. Rushed decisions, tired climbers, and a shrinking safety margin are a difficult combination on any 8,000-meter peak. Our Team's Highest Point: 7,100 Meters Our team completed two full rotations to prepare for the summit push, and once the route was fixed, we climbed to 7,100 meters, the highest point reached by any team on Manaslu this season. Reaching that height took real skill, discipline, and teamwork from our Sherpa staff and our clients. From there, the combination of unstable snow, the recent avalanche, and the approaching storm made it clear that going higher was not worth the risk. We turned back. ACE Team's Acclimatization Rotation Not Alone: How the Rest of the Mountain Responded Our decision was not made in isolation. As conditions worsened, a large number of operators on Manaslu came to the same conclusion, ending their seasons and sending their climbers home. Almost all teams on the mountain have now left. A small number remain at Base Camp, hoping for one more weather window, but current forecasts make that increasingly unlikely, and it's likely most of them will also head home before the season is out. Seeing so many experienced teams and guides reach the same decision, independently, said a lot about how serious this season's conditions really were. This was not one operator being overly cautious. It was a mountain-wide judgment call. A Message: Respect the Mountain Manaslu did not give us the summit this year. It gave us something else instead: a clear reminder of where we stand next to a mountain like this. We are not greater than nature. No amount of preparation, experience, or determination changes that. The avalanche danger, the storm, the loss of life this season, none of it cared about summit dreams or expedition budgets. The mountain simply did what mountains do, and our job was to listen. We believe real mountaineering is not only about reaching the top. It is about knowing the mountain deserves your respect more than your ambition does. This season asked a lot of every team on Manaslu, and we are proud that ours listened when it mattered most. Manaslu will still be there next year. So will we, and we'll return when conditions, and the mountain, are ready to welcome us back. About Alpinist Climber Expeditions Alpinist Climber Expeditions has run Himalayan climbs and treks in Nepal since 2021, guided by IFMGA-certified mountain guides and experienced Sherpa climbing staff. Safety has always come first in every decision we make, on Manaslu and every mountain we climb.

Sep 23, 2026 Read More →

Lenka Poláčková Makes History on Everest Without Supplemental Oxygen

Expedition Overview

Who Is Lenka Poláčková?

The Route: Everest by the South Col

Climbing Without Oxygen: What It Asks From a Climber

Waiting for the Right Day

Summit Day: 21 May 2024