Breathing cold and very dry air can additionally cause irritation and drying of the mucous membranes of the upper respiratory tract. This weakens their defense functions and increases susceptibility to infections. To counteract this, it is recommended to breathe through a buff, mask, or dedicated mask.

WHY IS IT EASY TO GET DEHYDRATED IN THE MOUNTAINS?

During acclimatization, the body produces more urine than at lower altitudes. This is a natural physiological mechanism – excess bases that appear in the body due to accelerated breathing are removed with urine.

In practice, this means:

➤ more frequent urination during the day

➤ nighttime awakenings to "pee"

➤ greater loss of water from the body

Additionally, water loss occurs through:

➤ breathing dry air

➤ sweating during exertion

It is estimated that at an altitude of about 4000 m above sea level, during a calm walk, we lose through breathing even:

➤ about a glass of water per hour

➤ which is about 1 liter during 5 hours of walking

Therefore, without regularly drinking several liters of fluids daily (at least 4 liters), dehydration is almost certain.

Symptoms of dehydration include:

➤ headache

➤ fatigue

➤ intense thirst

Therefore, it's worth drinking water with added electrolytes.

A good indicator of hydration is the color of urine. If you urinate light-colored urine about four times a day, it means that the body is well-hydrated and the acclimatization process is proceeding correctly.

HYDRATION AND BLOOD AT ALTITUDE

At high altitudes, the body produces more red blood cells, which help transport the limited amount of oxygen.

However, this also has a downside – the blood becomes thicker and stickier.

To counteract this, it is necessary to drink the right amount of fluids. The simplest rule is: drink enough so that the traces left on the snow are light or almost invisible – not dark yellow.

HYDRATION SYSTEM DURING CLIMBING

One practical way to combat dehydration is to use a 2-liter hydration bladder carried on the back (e.g., Camelbak).

Why is this a good solution?

➤ it is lighter than a thermos

➤ it allows you to carry more fluids

➤ it enables drinking without stopping and taking off the backpack

From the experience of many climbers, it turns out that:

➤ the water bag always gets emptied

➤ the thermos often returns from the mountain half full because it is not taken out of the backpack during climbing

HOW TO PREPARE WATER IN CAMP

One of the basic activities during high-altitude expeditions – right after climbing – is "making water," i.e., melting snow or ice.

Upon reaching camp, it is worth first:

➤ collecting snow or ice

➤ packing it into bags (e.g., sleeping bag or trash bags)

The melted water is then used for:

➤ drinking after exertion

➤ preparing meals

➤ preparing a water supply for the morning and the next day's climb

Evening is the best time for this, as there is usually very little time in the morning.

HOW TO PREVENT WATER FROM FREEZING IN THE CAMELBAK SYSTEM

The best solution is to carry the bladder under the jacket and only put the backpack on over the jacket.

This way:

➤ the initially warm liquid warms the back

➤ later, body heat maintains the liquid's temperature

➤ the tube is close to the body and is also heated

Important rule:

After each sip, you should blow into the tube to push the water back into the bag. If the liquid remains in the tube, it can freeze quickly. When you blow out all the water from the tube, you will feel a characteristic bubbling in the bag on your back.

NIGHT AWAKENINGS

For the expedition, it is worth taking a large bottle for urinating in the tent. For women, special devices that allow urinating while standing, such as Shewee, can be helpful. In older men, an enlarged prostate is often a common cause of nighttime awakenings, so it's advisable to consult a urologist before the expedition.

SAFE WATER IN THE MOUNTAINS

Before the trip, you should plan a method for disinfecting water.

In many mountainous regions:

➤ access to clean water is limited

➤ bottled water is not always available

The safest methods are:

➤ boiling water to a rolling boil

➤ using travel filters

➤ using disinfectants

One of them is iodine.

If you are not allergic to iodine, have no thyroid problems, and are not pregnant, you can use: 5 drops of 2% iodine per 1 liter of water.

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DO YOU WANT TO LEARNMORE?

If you want to better prepare yourself health-wise for trekking or a high-altitude expedition, you can find the extended version of the guide in the ebook"High Altitude Medicine in Practice – A Guide for Trekking and Expeditions" >>

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You will also learn practical knowledge about how to act in emergency situations in the mountains in the online training"High Altitude First Aid" >> - designed for those planning trips to high altitudes.

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Meanwhile, you will find a detailed list of the expedition first aid kit and a precise guide on how to prepare an expedition first aid kit and personal rescue kit in the ebook"Expedition First Aid Kit – A Complete Medical Guide" >>

PLANNING A TREKOR A HIGH-ALTITUDE EXPEDITION?

If you want to check whether your health allows you to safely participate in a trek or high-altitude expedition, it is worth consideringa medical consultation >> or a telemedicine expedition package >>

This way, you can assess health risks in advance, prepare adequately for the trip, and increase safety while at altitude.

07 March 2026

The company was established in 2004. The goal of MedEverest is education in the field of mountain medicine and the dangers of high altitudes. I deal with all medical aspects of staying at high altitude. I organize medical support for trekking and high-altitude expeditions.

Specialist Medical Practice Medeverest Robert Szymczak based in Gdańsk (80-360), at ul. Bolesława Krzywoustego 19F, NIP: 5841943576, REGON: 220148318.

Also checkStore regulations >> Implementation: ColinMedia.eu >>