Kargil Vijay Diwas: What it takes to live and fight at 18,000 feet in -40°C temperature

If you ever wonder what courage looks like, imagine standing guard at over 18,000 feet, in temperatures that can plunge below -40°C, where every breath is a struggle and survival itself is a daily challenge.

Every year on Kargil Vijay Diwas, India remembers the extraordinary courage and sacrifice of the soldiers who defended our nation's borders in the Kargil conflict. Many of our armed forces continue to serve in some of the world's harshest environments, including the Siachen Glacier, often called the highest battlefield on Earth. While the enemy is one challenge, nature itself becomes another formidable adversary.

For the average person, spending a few hours at such altitudes can cause breathlessness and fatigue. Our soldiers spend weeks to months carrying heavy equipment, patrolling icy terrain, and remaining constantly vigilant. Their resilience is a remarkable combination of physical fitness, careful preparation, disciplined training, and mental toughness.

Why is high altitude so challenging?

The main problem is not a lack of oxygen in the air but lower atmospheric pressure. As altitude increases, the amount of oxygen entering the bloodstream with each breath decreases. At 5,500–6,000 metres (18,000–20,000 feet), where many military posts are located, the body receives significantly less oxygen than at sea level.

The environment adds further stress:

• Temperatures can fall below –40°C 

• Strong winds increase heat loss 

• Snow reflects intense ultraviolet (UV) radiation 

• Air is extremely dry, leading to dehydration 

• Walking even short distances becomes physically demanding 

Without proper acclimatisation, these conditions can overwhelm even a healthy individual.

How does the body adapt?

The human body is remarkably adaptable. Over several days to weeks, it undergoes important changes:

• Breathing becomes faster and deeper. 

• Heart rate initially increases. 

• The kidneys help maintain the body's acid-base balance. 

• More red blood cells are produced to improve oxygen transport. 

• Muscles gradually become more efficient at using oxygen. 

This process, known as acclimatisation, is the reason soldiers are never rushed directly to extreme altitudes. They ascend gradually over several days, allowing their bodies to adapt and greatly reducing the risk of altitude illness.

Health risks at high altitude

Despite meticulous preparation, several medical problems remain common.

Acute Mountain Sickness (AMS) is the most frequent. Symptoms include headache, nausea, fatigue, dizziness, poor sleep, and loss of appetite. Most cases improve with rest and acclimatisation.

More dangerous are two life-threatening conditions:

• High-Altitude Pulmonary Edema (HAPE), where fluid accumulates in the lungs, causing severe breathlessness and cough. 

• High-Altitude Cerebral Edema (HACE), where swelling of the brain causes confusion, poor coordination, altered consciousness, and can rapidly become fatal. 

These are medical emergencies requiring immediate descent, oxygen therapy, and urgent treatment.

Cold exposure presents another set of challenges.

Frostbite can permanently damage fingers, toes, ears, and the nose when tissues freeze. 

Hypothermia, a dangerous drop in body temperature, can impair thinking, coordination, and heart function.

The intense UV radiation reflected by snow can also cause snow blindness, a painful inflammation of the cornea that temporarily impairs vision.

How do soldiers cope?

Military personnel undergo rigorous physical conditioning long before deployment. Equally important are specialised survival strategies.

Layered clothing traps warm air while allowing moisture to escape. Waterproof outer garments protect against snow and wind. High-quality gloves, insulated boots, and face protection minimize heat loss.

Hydration is another priority. Surprisingly, dehydration is common at high altitude because the cold suppresses thirst while rapid breathing increases water loss. Soldiers are encouraged to drink fluids regularly even when they do not feel thirsty.

Nutrition also plays a crucial role. High-energy meals rich in carbohydrates help provide readily available fuel in oxygen-poor conditions. Adequate protein supports muscle repair, while healthy fats provide sustained energy. Warm beverages improve comfort and encourage fluid intake.

Sleep, however, often remains difficult. High altitude commonly causes fragmented sleep and frequent awakenings. Maintaining regular sleep schedules and ensuring adequate rest become essential for recovery.

Do soldiers need medicines or supplements?

The cornerstone of prevention is gradual acclimatization, not medication.

In selected situations, doctors may prescribe acetazolamide to reduce the risk of acute mountain sickness during ascent.

Individuals at particularly high risk may occasionally require other medications under strict medical supervision. Supplemental oxygen is reserved for emergencies or certain operational situations rather than routine use. Routine vitamin supplements are generally unnecessary if nutritional intake is adequate. However, because prolonged deployment limits sunlight exposure and fresh food availability, military medical teams ensure that nutritional requirements are met through carefully planned diets. Vaccinations recommended for all military personnel are kept up to date, but there are no vaccines specifically for high altitude.

Can ordinary people prepare for high-altitude travel?

Whether trekking in the Himalayas or visiting high-altitude destinations, the same principles apply:

• Ascend gradually whenever possible. 

• Allow time for acclimatization. 

• Stay well hydrated. 

• Eat regular carbohydrate-rich meals. 

• Avoid excessive alcohol and sedative medications. 

• Recognise early symptoms of altitude illness. 

• Never ignore severe headaches, breathlessness at rest, confusion, or difficulty walking; these require immediate medical attention. 

Physical fitness certainly helps with trekking, but it does not prevent altitude sickness. Even elite athletes can develop serious altitude-related illnesses.

As we commemorate Kargil Vijay Diwas, we honor not only the bravery of our soldiers in battle but also their extraordinary ability to endure one of the planet's most unforgiving environments. Every patrol across icy terrain, every sleepless night in sub-zero temperatures, and every breath taken in oxygen-thin air is a testament to their discipline, resilience, and unwavering commitment.

While most of us experience high altitude as tourists for a few days, our soldiers live and work there for months, protecting our borders under conditions that continually test the limits of human endurance. Their courage reminds us that true strength is not merely physical. It is the quiet determination to keep going despite hardship, discomfort, and danger.

The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.