How to prevent, recognize, and act against hypothermia in the mountains?

Cold is part of many experiences in the mountains, but it doesn't always present itself in an obvious way. A day can start with good conditions and quickly change with the arrival of wind, rain, snow, or a sudden drop in temperature.

If the clothing is also wet, the route takes longer than expected, or someone is exhausted, the body can begin to lose heat faster than it can produce it. When that loss continues, hypothermia appears.

It's not just about feeling cold or having cold hands. It is a medical emergency that progressively affects the ability to move, think clearly, and make decisions. Precisely for this reason, it can be difficult to recognize, as the affected person may not understand that their condition is worsening.

Identifying the early signs and acting before confusion appears can prevent a manageable situation from turning into a complex evacuation.

What is hypothermia?

Hypothermia occurs when the body's core temperature drops to 35 °C or lower. In the mountains, however, a suitable thermometer to measure it is rarely available, so the assessment usually relies on symptoms and the person's behavior.

The body tries to defend itself from the cold by reducing blood flow to the skin and producing shivers to generate heat. These responses consume a lot of energy and have a limit. If cooling continues, the brain, muscles, breathing, and heart begin to function more slowly.

Although it is often associated with snow or sub-zero temperatures, it can also occur in relatively cool environments. A person wet from rain, sweat, or falling into a river can cool down quickly if they remain exposed to the wind or spend too much time without moving.

Therefore, the risk does not solely depend on the outside temperature. Humidity, wind, fatigue, lack of food, an injury, and prolonged exposure can combine to exceed the body's ability to stay warm.

Why can it appear during a hike?

In trekking and mountains, there are several ways to lose heat simultaneously. The wind removes the layer of warm air surrounding the body, wet clothing accelerates cooling, and contact with the cold ground continues to extract heat even when the person is covered.

A common situation occurs during a demanding ascent. The person sweats, wets their base layer, and continues walking without adjusting their insulation. When stopping at a summit, waiting for the group, or being exposed to a gust, that moisture begins to cool on the skin.

It can also happen if the route extends into the night, food runs out, the weather worsens, or someone suffers an injury that prevents them from continuing to move.

Hypothermia rarely begins with a single major mistake. It generally appears after a series of small problems that were not corrected in time.

What are the first symptoms?

In an early stage, the person usually remains conscious and can still talk, walk, and answer questions. Intense shivering is one of the most recognized signs, but it is not the only one.

Unusual fatigue, clumsiness when handling objects, loss of sensitivity in the hands, difficulty closing a backpack, walking slower, or frequently stumbling may also appear. Simple tasks that normally wouldn't pose problems begin to require too much effort.

Changes in behavior are especially important. The person may become irritable, indifferent, too quiet, or make decisions that do not correspond to the situation. They may even insist that they are fine despite showing clear signs of deterioration.

Not everyone who shivers necessarily has hypothermia, but if shivering is accompanied by clumsiness, exhaustion, or an inability to care for oneself, it is safest to stop and begin to act.

Signs that require urgent evacuation

As cooling progresses, the person may start to speak slowly, slur their words, become confused, respond incoherently, or lose their balance. Marked drowsiness that does not correspond solely to fatigue from the hike may also appear.

The decrease or disappearance of shivering while the person remains cold is a particularly concerning sign. It does not mean they have warmed up. It may indicate that their body no longer has enough energy to continue producing heat through muscle movement.

Inability to walk without assistance, loss of coordination, slurred speech, altered consciousness, or abnormal breathing should be considered signs of more advanced hypothermia.

In these cases, the priority is no longer to complete the route. The person needs protection, careful handling, and evacuation as soon as possible.

Prevention begins before leaving

Preventing hypothermia starts with realistic planning. Before choosing a route, it is advisable to check the forecast, the wind chill, wind speed, the possibility of rain or snow, and the available daylight hours.

The itinerary should consider the elevation gain, the state of the terrain, breaks, and the experience of those participating. Planning using only the time indicated in an app can leave very little margin in the face of slow progress, an injury, or a change in weather.

It is also important to define a return deadline. This decision prevents continuing to advance out of enthusiasm when there is no longer enough time to return with daylight or face an unforeseen event.

Inside the backpack, there should be a hat, gloves, waterproof jacket, a dry layer protected in a bag, a thermal blanket, an insulating pad, and easy-to-consume food. On remote routes, it may also be necessary to have items to improvise a shelter and communicate in case of emergency.

Regulate clothing before getting soaked

Dressing in layers does not mean using all available clothing from the start. If you start an ascent with too much insulation, you will likely begin to sweat within minutes.

It is advisable to open vents or remove a layer before the clothing becomes wet. When you stop, you should put on more insulation before you start to shiver.

A first technical layer helps transport moisture, a mid-layer retains heat, and an outer layer protects against wind and precipitation. Cotton is not a good alternative for cold conditions because it absorbs water and takes too long to dry.

Spare clothing should be stored in a waterproof bag. Carrying a dry shirt loses all utility if it ends up wet inside the backpack due to rain or a poorly closed bottle.

Maintain energy during the hike

The body needs energy to produce heat. A person who has been walking for many hours, has eaten little, or is dehydrated will have less capacity to face the cold.

On long routes, it is advisable to eat and drink regularly, without waiting until feeling intense hunger or thirst. This is especially important in winter, when low temperatures can diminish the sensation of thirst.

Alcohol should never be used to warm up. It can produce a momentary feeling of warmth on the skin, but it promotes heat loss and decreases the ability to assess risk.

It is also important to observe the rest of the group. Asking how they feel, checking that no one is wearing completely wet clothing, and adapting the pace to the slowest person can help detect a problem before it advances.

What to do in case of possible hypothermia?

When symptoms appear, the priority is to stop the cooling. The person should not be forced to continue walking without first assessing their condition.

A simple way to organize the response is to remember four ideas. Isolate, warm, provide energy when safe, and monitor.

These actions do not replace medical attention or first aid training, but they can help protect the person while organizing the evacuation.

Step 1: Protect from the weather and insulate from the ground

The first step is to get the person out of the wind, rain, or snow. A tent, shelter, tarp, waterproof layer, or any barrier that reduces exposure can be used.

They should also be insulated from the ground using a mat, backpacks, rope, dry clothing, or other available material. Covering them only from above is not enough if they continue lying directly on a cold surface.

The head and neck should be protected, but the face and airway must remain clear.

Step 2: Replace wet clothing and warm

Once the person is protected from the environment, it is advisable to remove wet clothing and replace it with dry garments. If removing it requires too much movement or there is no protected place, it may be necessary to cut it off or temporarily wrap the person to prevent further heat loss.

They should then be covered with dry clothing, blankets, insulating pads, or a sleeping bag. The thermal blanket can help reduce heat loss, but it does not produce heat on its own and works best as part of an insulating system.

If a sleeping bag is available, it is preferable to place the person inside and close it rather than using it only as a blanket.

Step 3: Apply heat to the torso

External heat sources should be placed primarily on the chest, armpits, and upper back. Warm water bottles, active blankets, or compresses designed for this purpose can be used.

They should never be placed directly on the skin. It is necessary to wrap them in a cloth to avoid burns, as a very cold person may have reduced sensitivity and not notice the damage.

Do not start by intensely warming hands and feet, massaging the extremities, or immediately placing the person in a very hot shower or bath. Initial rewarming should focus on the center of the body and be done in a controlled manner.

Step 4: Provide food and drinks only if they can swallow

A fully alert person, able to sit, converse clearly, and swallow without difficulty can receive carbohydrate-rich foods and a warm drink.

The liquid does not need to be very hot. An excessive temperature can cause burns and does not significantly accelerate recovery.

Foods and drinks should not be given to a confused person, very drowsy, nauseous, unable to swallow, or unconscious, due to the risk of aspiration.

Step 5: Monitor and handle with care

The person should not be left alone. It is necessary to observe their breathing, level of consciousness, coordination, and ability to answer simple questions.

They should also be handled gently, especially if they show confusion, have stopped shivering, or cannot walk. Sudden movements and unnecessary effort can increase the risk of complications in advanced hypothermia.

If their condition worsens, they lose coordination, or stop responding clearly, any attempt to continue the route on their own should be abandoned.

Step 6: Activate evacuation in time

It is not necessary to wait until the person loses consciousness to request help. Evacuation should be prioritized in the face of confusion, slurred speech, marked drowsiness, loss of coordination, absence of shivering, difficulty breathing, or lack of improvement.

It should also be activated if the group does not have means to keep them protected, if there is still a considerable distance left, or if weather conditions will continue to deteriorate.

A person with moderate or severe hypothermia should not be forced to walk. Whenever possible, they should be kept horizontal and moved carefully.

If they are unconscious and not breathing normally, emergency services should be activated immediately, CPR should be started if the helper knows how to perform it, and a defibrillator should be used when available.

Is it advisable to walk to regain temperature?

Movement produces heat, but it should not always start immediately. A person who is shivering may benefit first from a period of rest protected from the environment, with insulation and energy supply.

If they remain fully alert, have regained stability, and can stand up without difficulty, they may begin to walk gradually and under observation. Activity should stop if their condition worsens again.

In contrast, a confused, uncoordinated, extremely tired person, or one who has stopped shivering should not be forced to move. In that scenario, the priority is to conserve their temperature and organize evacuation.

Errors that can worsen the situation

One of the most dangerous mistakes is assuming that the disappearance of shivering means recovery. If the person remains cold, it may indicate that the condition is advancing.

Intense heat sources should not be applied directly to the skin, arms and legs should not be rubbed, nor should very hot baths be used as a first measure.

Giving alcohol, offering liquids to someone who cannot swallow, or insisting that they keep walking despite showing confusion can also increase the risk.

Another common mistake is waiting too long before asking for help. In remote places, evacuation can take several hours, so it is advisable to activate it while there is still light, communication, and the ability to protect the person.

Act before the cold makes the decisions

Hypothermia does not usually begin with a dramatic scene. It can present as clumsy hands, unexpected fatigue, persistent shivering, or a person who gradually starts to fall behind.

These early signs offer an opportunity to stop, seek shelter, and modify the plan before the affected person loses the ability to decide for themselves.

In the mountains, turning back, stopping, or changing a wet garment are not minor decisions. Many times, they are precisely the actions that prevent the cold from turning into an emergency.