Discover essential health and safety tips for trekking in Nepal’s high-altitude regions, including Everest, Annapurna, and Manaslu. Learn how to prevent altitude sickness, stay hydrated and nourished, maintain fitness, and respond to emergencies with guide-supported strategies.
Trekking in Nepal attracts thousands of travelers each year, drawn by the Himalayas and world-famous routes like Everest Base Camp, Annapurna Circuit, and Langtang Valley. Altitude health awareness is a cornerstone of safe trekking in Nepal.
Every trekker in Nepal should approach altitude with respect, preparation, and knowledge—ensuring a safer and more rewarding Himalayan experience.
Importance of Altitude Awareness in Nepal
Most trekking trails in Nepal range between 2,500 meters to over 5,500 meters above sea level. At these elevations, oxygen levels drop significantly, and the body must adapt gradually.
Trekkers who underestimate altitude often face problems that can derail an expedition or cause life-threatening emergencies.
Key reasons altitude awareness is vital in Nepal:
High Elevation Terrain: Popular routes such as Everest Base Camp (5,364m) and Annapurna Base Camp (4,130m) reach heights where altitude sickness is common.
Rapid Ascents: Some itineraries push trekkers to ascend too quickly, increasing risk.
Remote Locations: Evacuation in case of altitude illness is difficult and costly in the Himalayas.
Understanding Altitude for Trekking in Nepal
Altitude directly affects how the body performs during trekking in Nepal. Oxygen concentration decreases as elevation increases, making acclimatization vital. Trekkers must understand altitude levels and how they relate to health risks and trekking routes in the Himalayas.
Definition of Altitude Levels
Low Altitude (<1,500m)
Found in the Terai plains and lower hill regions of Nepal.
No risk of altitude sickness.
Common areas: Chitwan National Park, Kathmandu Valley (1,400m).
Moderate Altitude (1,500–2,500m)
Oxygen levels slightly reduced but generally well tolerated.
Minimal risk of altitude sickness.
Treks in this range: Ghorepani Poon Hill (3,210m maximum, but starting below 2,000m).
High Altitude (2,500–3,500m)
Significant reduction in oxygen levels.
AMS can occur if ascent is too rapid.
Common trails: Namche Bazaar (3,440m) on the Everest Base Camp trek, Manang (3,540m) on the Annapurna Circuit.
Very High Altitude (3,500–5,500m)
High risk of AMS, HAPE, and HACE without proper acclimatization.
Most major trekking routes in Nepal reach this zone.
Examples: Everest Base Camp (5,364m), Annapurna Base Camp (4,130m), Gokyo Lakes (4,700–5,000m).
Extreme Altitude (>5,500m)
Extremely low oxygen levels; prolonged exposure is dangerous.
Only mountaineering expeditions and high passes reach this level.
Examples: Kala Patthar (5,545m) for trekkers, and climbing peaks such as Island Peak (6,189m).
Major Trekking Regions in Nepal and Altitude Ranges
Everest Region: 2,800m at Lukla to 5,545m at Kala Patthar.
Annapurna Region: 800m at Pokhara to 5,416m at Thorong La Pass.
Langtang Region: 1,470m at Syabrubesi to 4,984m at Tserko Ri.
Manaslu Circuit: 700m at Soti Khola to 5,160m at Larke Pass.
Upper Mustang: 2,800m at Kagbeni to 4,200m at Lo La Pass.
Kanchenjunga Region: 1,200m at Taplejung to over 5,000m at Pangpema Base Camp.
Effects of Altitude on the Body
Trekking in Nepal involves rapid changes in elevation, and the human body reacts directly to reduced oxygen availability.
Understanding the effects of altitude helps trekkers recognize early warning signs and adjust their pace.
Reduced Oxygen and Hypoxia
At sea level, oxygen concentration in the air is about 21%. While this percentage does not change with altitude, air pressure decreases, reducing the amount of oxygen available per breath.
At 3,500m, oxygen availability is roughly 65% of sea level. This oxygen shortage, known as hypoxia, forces the body to adapt by producing more red blood cells and increasing breathing rate.
Impact on Respiration and Heart Rate
Respiration: At higher altitudes, the body compensates by breathing faster and deeper. This leads to lower carbon dioxide levels in the blood, which can cause lightheadedness.
Heart Rate: The heart pumps faster to deliver oxygen to tissues. Resting heart rate increases noticeably at altitudes above 2,500m, even without physical exertion.
Sleep Disturbances at Altitude
Sleep becomes irregular at elevations above 2,500m due to unstable breathing patterns known as periodic breathing. Trekkers often wake up suddenly gasping for air, which disrupts rest. Poor sleep quality can worsen fatigue, slow recovery, and increase the risk of altitude sickness.
Appetite and Digestion Changes
Altitude suppresses appetite, making it difficult for trekkers to maintain adequate calorie intake. At the same time, digestion slows because blood is prioritized for vital organs instead of the stomach. Reduced appetite combined with increased energy demands from trekking often leads to weight loss during high-altitude expeditions.
Altitude Sickness (Acute Mountain Sickness – AMS)
Altitude sickness is the most common health challenge faced by trekkers in Nepal. It occurs when the body fails to adapt properly to reduced oxygen at elevations typically above 2,500 meters. Recognizing and managing AMS is critical for safe trekking in the Himalayas.
What is AMS?
Acute Mountain Sickness (AMS) is a collection of symptoms caused by the body’s inability to acclimatize to high altitude. It ranges from mild discomfort to life-threatening complications if ignored. AMS can progress rapidly, making early detection essential.
Causes and Risk Factors
AMS develops when ascent is too fast for the body to adjust to lower oxygen availability. Several factors increase the risk:
Rapid ascent without rest or acclimatization days.
Sleeping altitude that is much higher than the previous night’s.
Individual susceptibility – some people are naturally more prone to AMS.
Previous history of altitude sickness.
Dehydration, alcohol, or sedative use, which interfere with acclimatization.
High exertion without adequate rest.
Symptoms of AMS
Mild AMS
Headache (most common early sign).
Nausea, loss of appetite.
Fatigue, dizziness, and difficulty sleeping.
Moderate AMS
Severe headache not relieved by medication.
Persistent nausea and vomiting.
Shortness of breath during rest.
Reduced coordination (ataxia).
Severe AMS
Confusion, inability to walk in a straight line.
Severe breathlessness at rest.
Bluish lips or fingernails (cyanosis).
Progression to HAPE (fluid in lungs) or HACE (swelling of the brain).
Risk of death if not treated with immediate descent.
Differentiating AMS from Other Illnesses
Altitude sickness shares symptoms with conditions like dehydration, exhaustion, and viral infections. The key differentiators are:
Headache plus other symptoms at altitudes above 2,500m strongly suggest AMS.
Symptoms worsen with increased altitude and improve with descent.
Unlike flu or food poisoning, AMS does not usually cause fever or diarrhea.
Severe Altitude Illnesses
While Acute Mountain Sickness (AMS) is common and often manageable, two severe altitude illnesses—High Altitude Pulmonary Edema (HAPE) and High Altitude Cerebral Edema (HACE)—are life-threatening emergencies.
High Altitude Pulmonary Edema (HAPE)
Causes
HAPE occurs when fluid accumulates in the lungs due to increased pressure in the pulmonary blood vessels at high altitude. It typically develops after rapid ascent above 3,000m, especially if acclimatization is insufficient. Cold conditions and overexertion increase risk.
Symptoms
Shortness of breath at rest.
Persistent dry cough progressing to frothy or pink sputum.
Extreme fatigue and weakness.
Crackling or bubbling sounds in the lungs when breathing.
Rapid heartbeat and blue lips or fingernails (cyanosis).
Treatment and Evacuation
Immediate descent is the single most effective treatment.
Supplemental oxygen if available.
Nifedipine, a medication that reduces pulmonary pressure, may be used under medical supervision.
Rest and keep the patient warm.
Emergency evacuation by helicopter may be required in Nepal’s remote trekking regions.
High Altitude Cerebral Edema (HACE)
Causes
HACE is caused by swelling of the brain due to fluid leakage from blood vessels under low-oxygen conditions. It usually develops from untreated AMS at elevations above 3,500m, often after rapid ascent.
Symptoms
Severe, unrelenting headache.
Loss of coordination (ataxia), difficulty walking in a straight line.
Altered mental state: confusion, irritability, hallucinations.
Slurred speech and vision problems.
Progression to drowsiness, coma, and death if untreated.
Treatment and Evacuation
Immediate descent of at least 500–1,000m is essential.
Supplemental oxygen can stabilize symptoms temporarily.
Dexamethasone (a steroid) may reduce brain swelling if available.
Keep the patient warm and never leave them unattended.
Rapid evacuation by helicopter is often the only option in remote Himalayan trekking routes.
Prevention of Altitude Sickness
Altitude sickness is largely preventable with proper planning and awareness. Trekkers in Nepal can reduce risk by following proven acclimatization techniques, safe ascent profiles, and healthy habits during their journey.
Fitness alone is not enough—safe acclimatization practices are essential for every trekker aiming to enjoy the Himalayas without health risks.
Acclimatization Techniques
Acclimatization is the process by which the body adapts to reduced oxygen at higher altitudes. The key principles are:
Ascend gradually to allow the body time to adjust.
Include rest days at strategic points (often every 1,000m gain in sleeping altitude).
Recognize and respond to early symptoms of AMS.
Recommended Ascent Profiles (300–500m Per Day Rule)
The gold standard for safe ascent is:
Do not increase sleeping altitude by more than 300–500 meters per day once above 2,500m.
For every 1,000m gained, take one acclimatization day.
If symptoms appear, do not ascend further until fully recovered.
Rest Days and the “Climb High, Sleep Low” Strategy
On rest days, trekkers should take acclimatization hikes to higher altitudes before returning to sleep at a lower elevation.
Example: From Namche Bazaar (3,440m), trekkers often climb to Everest View Hotel (~3,880m) before returning to Namche to sleep.
This technique helps the body adapt without overstressing it.
Hydration and Diet
Drink at least 3–4 liters of fluids daily to prevent dehydration, which worsens AMS symptoms.
Avoid excessive caffeine, but moderate tea and coffee are safe.
Eat a high-carbohydrate diet, which provides efficient energy at altitude.
Avoid heavy, fatty meals that slow digestion.
Role of Fitness vs. Acclimatization
Physical fitness improves stamina and endurance, but it does not prevent altitude sickness.
Even the fittest athletes can develop AMS if they ascend too quickly.
Acclimatization, not fitness, is the deciding factor in altitude safety.
Avoiding Alcohol, Smoking, and Sleeping Pills
Alcohol depresses breathing and accelerates dehydration, increasing AMS risk.
Smoking reduces oxygen delivery to tissues.
Sleeping pills and sedatives slow down breathing during sleep, making altitude effects worse.
Trekkers should avoid all three at high elevations.
Medical Support and Medication at Altitude
While prevention is the best defense against altitude sickness, trekkers in Nepal must also be prepared with knowledge of medication, oxygen support, and emergency responses.
Professional trekking guides play a crucial role in monitoring health, administering first aid, and coordinating evacuation when necessary.
Preventive Medicines (Diamox / Acetazolamide)
Diamox (Acetazolamide) is the most widely used preventive medication for AMS.
It works by stimulating breathing and speeding up acclimatization.
Usual preventive dose: 125–250 mg twice daily, starting 24 hours before ascent above 2,500m.
Diamox does not mask symptoms; it helps the body adapt faster.
Trekkers should consult a doctor before use and check for sulfa drug allergies.
Treatment Medicines for AMS, HAPE, and HACE
AMS: Diamox (continuing or starting treatment dose).
HAPE: Nifedipine can reduce high blood pressure in the lungs.
HACE: Dexamethasone reduces brain swelling temporarily until descent.
These medications are emergency measures, not substitutes for descent.
Oxygen Therapy and Portable Altitude Chambers (Gamow Bag)
Supplemental Oxygen: Carried on some guided treks, especially in the Everest region. Provides short-term relief from hypoxia but should not be used as a reason to continue ascending.
Gamow Bag (Portable Altitude Chamber): A sealed inflatable chamber that simulates descent by increasing air pressure around the patient. Useful in remote areas when immediate evacuation is not possible.
When to Descend
Descent is the most effective and life-saving treatment for altitude illness. Immediate descent is required if:
Symptoms of moderate to severe AMS do not improve with rest.
Signs of HAPE: breathlessness at rest, wet cough, bluish lips.
Signs of HACE: confusion, loss of coordination, inability to walk properly.
Even a descent of 500–1,000m can be lifesaving.
Role of Trekking Guides in Nepal
Experienced Nepali trekking guides are trained in altitude awareness and basic medical response. Their roles include:
Monitoring trekkers daily for AMS symptoms.
Enforcing acclimatization schedules and safe ascent profiles.
Administering first aid and advising on medication use.
Arranging helicopter evacuation in emergencies.
Using satellite phones or local networks to coordinate rescue operations in remote regions.
Experienced trekking guides and porters are trained to monitor symptoms, administer first aid, and coordinate evacuation.
They help manage medications, hydration, and rest schedules, ensuring the group responds quickly to health issues.
Places Nepal Treks ensures trekkers’ safety and well-being by providing expert-guided itineraries with proper acclimatization, daily health monitoring, emergency preparedness, safe nutrition, and personalized support for all age groups, allowing clients to enjoy high-altitude treks in Nepal with confidence and peace of mind.
Nutrition & Hydration at Altitude
Proper nutrition and hydration are critical for trekkers in Nepal’s high-altitude regions. The body requires more energy and fluids to function efficiently in low-oxygen environments. Inadequate diet or dehydration increases fatigue, slows acclimatization, and raises the risk of altitude sickness.
A well-planned, carbohydrate-focused diet combined with proper hydration supports energy, acclimatization, and overall health at high altitudes.
Importance of Carbohydrate-Rich Diet
Carbohydrates are the body’s primary energy source at altitude, as they require less oxygen to metabolize compared to fats or proteins.
Trekkers should prioritize rice, pasta, oats, potatoes, and energy bars during the trek.
Adequate carbohydrates help maintain stamina for long hiking days and support recovery during rest periods.
Caloric Needs at Higher Elevation
Energy demands increase by 10–20% at high altitude due to increased respiration and physical exertion.
Average trekking calories: 3,000–4,000 kcal per day, depending on trek difficulty and individual metabolism.
Include small, frequent meals to maintain consistent energy levels and avoid gastrointestinal discomfort.
Hydration Strategies
Drink 3–4 liters of water daily, more if the trek is physically demanding or in dry, cold regions.
Monitor hydration using urine color: pale yellow indicates adequate hydration; dark yellow suggests dehydration.
Avoid excessive caffeine or alcohol, which contribute to fluid loss.
Electrolyte solutions can help replace salts lost through sweat and prevent dehydration-related headaches.
Foods to Avoid at Altitude
Heavy, fatty foods (fried foods, large amounts of meat) that slow digestion.
Excess sugar and processed snacks, which can cause energy crashes.
Alcohol and sedatives, which depress respiration and worsen hypoxia.
Foods that increase gas or bloating (beans, carbonated drinks) can make breathing uncomfortable at high altitude.
Fitness Preparation and Training for High-Altitude Trekking
Physical fitness is an essential component of safe and enjoyable trekking in Nepal. While fitness alone does not prevent altitude sickness, it improves endurance, reduces fatigue, and supports recovery during long days at high elevations.
Cardiovascular Training for Trekking
Purpose: Enhances heart and lung efficiency, allowing the body to deliver oxygen more effectively to muscles.
Recommended Exercises:
Running, jogging, or brisk walking.
Cycling and swimming to improve aerobic capacity.
Stair climbing or hiking with a weighted backpack to simulate trekking conditions.
Frequency: 4–5 times per week, gradually increasing intensity and duration.
Strength and Endurance Exercises
Leg Strength: Squats, lunges, step-ups, and calf raises improve stability on uneven terrain.
Core Strength: Planks, sit-ups, and back extensions enhance balance and posture during long treks.
Endurance: Long hikes with progressively heavier backpacks prepare muscles for sustained activity over several days.
Include flexibility and stretching routines to reduce injury risk.
Mental Preparation for High Altitude
Trekking at high altitude, mental resilience is critical for coping with fatigue, discomfort, and environmental stress.
Visualization Techniques: Imagine successfully completing each stage of the trek to build confidence.
Mindfulness and Breathing Exercises: Help manage stress, maintain calm, and regulate breathing in low-oxygen conditions.
Setting Realistic Goals: Plan daily distances according to fitness and acclimatization schedules; avoid overexertion.
Mental preparation also includes awareness of AMS symptoms, knowing when to rest or descend, and trusting guide instructions.
Trekking Safety and Monitoring Health
Using self-assessment, pulse oximeters, and guide support allows trekkers to respond promptly to altitude stress, maintaining safety and enhancing the trekking experience.
Recognizing Early Warning Signs
Trekkers should watch for headache, dizziness, nausea, fatigue, shortness of breath, and sleep disturbances. Early recognition helps prevent AMS, HAPE, or HACE.
The Lake Louise Score (LLS) tracks symptoms like headache, fatigue, and sleep quality to gauge AMS severity. Keeping a daily symptom journal also helps monitor acclimatization.
Monitoring Heart Rate and Oxygen Saturation
A pulse oximeter measures oxygen saturation (SpO₂) and pulse. Values below 85–88% at rest indicate risk, signaling the need for rest, oxygen, or descent.
Group Support and Guide’s Role
Guides monitor trekkers for symptoms, enforce acclimatization schedules, and coordinate emergency response. Group vigilance ensures early detection and safe decision-making.
Emergency Evacuation in Nepal
Planning for emergency descent, carrying proper insurance, and relying on guide-supported communication ensures safety in Nepal’s high-altitude trekking regions.
When and How to Descend Safely
Immediate descent is essential for moderate to severe AMS, HAPE, or HACE. Trekkers should move 500–1,000m lower or to the nearest safe location while resting and using oxygen if available.
Availability of Rescue Helicopters
Nepal has helicopter rescue services for high-altitude emergencies, particularly in Everest, Annapurna, and Langtang regions. Helicopter evacuations are often the fastest way to reach medical care in remote areas.
Insurance Requirements for Evacuation
Trekking insurance covering high-altitude helicopter evacuation and medical treatment is mandatory for safety and should be arranged before departure.
Communication Systems in Remote Areas
Satellite phones, local SIM networks, and trekking agency radios are essential for emergency contact, as mobile coverage is limited in high-altitude regions.
Role of Places Nepal Treks Team
Experienced teams like Places Nepal Treks coordinate evacuation, arrange helicopters, and guide trekkers safely to lower altitudes or medical facilities.
Children, Elderly, and Special Groups: Trekking in Nepal
High-altitude trekking in Nepal presents unique challenges for vulnerable groups, including children, the elderly, and individuals with specific health conditions. Awareness of risks and careful planning are essential to ensure safety.
Risks and Precautions for Children
Children are more susceptible to Acute Mountain Sickness (AMS) due to smaller lung capacity and less efficient acclimatization.
Rapid ascent increases risk; gradual climbs with frequent rest days are mandatory.
Hydration, high-carbohydrate diets, and monitoring for fatigue, nausea, or headaches are critical.
Children should avoid extreme altitudes above 4,000m, as their risk of severe AMS rises significantly.
Elderly Trekkers and Pre-Existing Conditions
Age-related changes in cardiovascular and respiratory systems increase vulnerability to hypoxia.
Pre-existing conditions—heart disease, hypertension, diabetes, or respiratory illness—require medical clearance before trekking.
Slow ascent, regular rest days, and monitoring oxygen saturation and heart rate help reduce complications.
Elderly trekkers should carry emergency medication and communication devices for immediate assistance.
Women’s Health at Altitude
Pregnancy at high altitude carries increased risk of hypoxia for mother and fetus; trekking above 2,500–3,000m is generally not recommended.
Menstrual symptoms may intensify at altitude due to dehydration and fatigue.
Adequate hydration, nutrition, and pacing are essential for all female trekkers.
Women with chronic conditions or pregnancy must seek medical advice before planning high-altitude treks.
Common Health Issues Beyond Altitude
Hypothermia and Frostbite – Cold temperatures in high-altitude regions can cause hypothermia and frostbite; proper layering, gloves, and insulated footwear are essential.
Sunburn and Snow Blindness – Strong UV exposure at altitude can damage skin and eyes; use sunscreen, sunglasses, and protective clothing.
Dehydration and Diarrhea – Reduced humidity and increased exertion raise dehydration risk; maintain fluid intake and eat safe, clean food.
Blisters, Sprains, and Minor Injuries – Long trekking days increase the risk of blisters, ankle sprains, and cuts; wear well-fitted boots and carry a basic first-aid kit.
Respiratory Infections – Cold, cough, and bronchitis are common due to low temperatures and dusty conditions; rest, hydration, and timely medication help recovery.
First Aid & Health Kit for Trekking
Carrying a well-prepared first aid and health kit is essential for safe trekking in Nepal’s high-altitude regions. Proper supplies can prevent minor issues from becoming serious health risks.
Essential Medicines to Carry
Altitude-related: Diamox (Acetazolamide) for AMS prevention, Nifedipine for HAPE, Dexamethasone for HACE.
Pain and fever: Paracetamol or ibuprofen.
Digestive health: Anti-diarrheal (Loperamide), rehydration salts, antacids.
Cold and cough: Cough syrup, lozenges, decongestants.
Allergies and insect bites: Antihistamines and topical creams.
First Aid Supplies
Bandages, adhesive tape, gauze pads, and antiseptic wipes.
Blister pads, elastic bandages, and cold packs.
Thermometer and basic instruments (scissors, tweezers).
Portable oxygen, face masks, and a Gamow bag (for emergencies at high altitude).
Traditional and Local Remedies in Nepal
Trekking in Nepal exposes visitors to high-altitude challenges, and many trekkers encounter traditional remedies and herbal practices used by local communities. While these practices have cultural significance, understanding their limitations is essential for safety.
Local Herbal Practices and Foods
Herbal teas made from ginger, tulsi (holy basil), or local mountain herbs are commonly used to ease digestion, cold, or mild altitude discomfort.
Yak butter tea provides quick calories and hydration in cold, high-altitude regions.
Honey, ghee, and local grains are used for energy and mild anti-inflammatory effects.
Many lodges and villages serve home remedies for headaches, fatigue, and stomach upset.
Limitations Compared to Modern Medicine
Traditional remedies may relieve mild symptoms but cannot prevent or treat serious conditions like AMS, HAPE, or HACE.
Dosages and efficacy are inconsistent, and remedies may interact with prescription medications.
Relying solely on local remedies without proper acclimatization, preventive medication, or medical supervision can be dangerous at high altitude.
Mental Health at High Altitude
Trekking in Nepal’s high-altitude regions, such as the Manaslu Circuit, challenges both the body and mind. Psychological effects of altitude, combined with isolation and physical exertion, can impact mental well-being during multi-day treks.
Psychological Effects of Altitude and Isolation
Hypoxia (low oxygen) can cause mood changes, irritability, and difficulty concentrating.
Remote trekking areas like Manaslu have limited communication, increasing feelings of isolation and stress.
Sleep disturbances at high altitude contribute to fatigue and reduced emotional resilience.
Coping with Fatigue, Anxiety, and Altitude Stress
Pacing and rest: Follow gradual ascent schedules and incorporate rest days for mental recovery.
Breathing exercises and mindfulness: Slow, deep breathing and meditation help manage anxiety and improve oxygen efficiency.
Group support and guides: Trekking with experienced guides or team members reduces isolation and ensures early recognition of mental or physical distress.
Light activity and nutrition: Maintaining energy through small, frequent meals and hydration supports both physical and mental endurance.
Case Studies & Real Examples of Altitude Illness in Nepal
Real-life examples from Nepal’s most popular trekking routes underscore that altitude illness is predictable and preventable.
Routes like Everest Base Camp, Annapurna Circuit, and Manaslu Circuit have reported altitude-related incidents that highlight the importance of acclimatization, monitoring, and emergency preparedness.
Famous Incidents of Altitude Illness
Everest Base Camp: Several trekkers have suffered HAPE and HACE above 5,000m due to rapid ascent from Namche Bazaar without proper acclimatization. Helicopter evacuations were critical in saving lives.
Annapurna Circuit: Cases of moderate to severe AMS have occurred at Thorong La Pass (5,416m) when trekkers ignored rest days and increased sleeping altitude too quickly.
Manaslu Circuit: Trekkers at Larke Pass (5,160m) experienced fatigue, nausea, and headaches due to insufficient hydration and acclimatization, emphasizing the need for guide support and pacing.
Lessons Learned
A gradual ascent is essential because even experienced trekkers are at risk of altitude sickness when climbing too quickly. Monitoring and early response save lives, with tools like pulse oximeters, the Lake Louise Score, and vigilant guides playing a critical role. Emergency preparedness is vital, as helicopter evacuation, medical kits, and trekking insurance provide lifesaving support in remote Himalayan regions. Incorporating rest and acclimatization days helps prevent mild AMS from progressing into life-threatening conditions such as HAPE or HACE.
