Hypothermia
Hypothermia occurs when the body loses heat faster than it can generate it, leading to a situation where the body core is unable to maintain sufficient warmth to allow the proper function of vital organs.

Wet, wind and cold are the key environmental factors that cause hypothermia. Any two of these is enough to start the cooling process in earnest.

As you move it is important to vent the moisture your body is creating as you exert yourself. At the same time you will attempt to protect yourself against the wind and rain. It is vital to keep your base layer as dry as possible, as wet or damp clothing against your body will cause you to lose heat 25 times faster than when dry.

A few degrees is all it takes!
Normal body core temperature is 37C. The skin is usually cooler by a few degrees.

Shivering occurs when core temperature 35C. The body is automatically trying to produce warmth by muscular activity.

Below 35C, we start to experience clumsiness, irrational behaviour and generally confused state. A person may appear to be drunk. At this stage the person suffering is almost exhausted and unable to produce body heat, let alone keep moving. Exercising the person will only increase the hypothermia. It would be dangerous to take the person suffering from hypothermia into a warm room as it can cause the blood to rush from the core to the extremities which suddenly may sent the person into a coma.

At 33C the person will be shivering, incoherent and complain of aching stiff muscles. They are now on the edge of severe hypothermia. If the temperature continues to drop they will slip into unconsciousness and may lose response to painful stimulus.

At 28C the person will give the appearance of death. It is important not to give up on treatment. There have been several cases where the person has made a full recovery having been kept alive by rescue breathing and CPR for several hours! For this reason a doctor will only pronounce the person dead when the body has returned to room temperature.

Awareness and prevention
Dealing with a hypothermic case in the wilds is very difficult and it is better to concentrate on spotting the symptoms and prevent it occurring, rather than trying to reheat a patient. Which could be you if you are travelling solo!

Before you start
Ensure you and everyone in your party is carrying the right layering material to suit the weather conditions you are walking in and you willingly stop regularly to out them on. In essence you want to try and keep your base layer as dry as possible by continually varying your layers to suit your activity and weather conditions.

Why layer
As explained, a base layer which wicks moisture away from your skin is vital to prevent the increase of heat loss. A simple highly breathable windshirt prevents windchill/convection. An insulating layer which you put on at rest stops or periods of low activity keep the heat in. Finally a waterproof jacket to prevent rain or cold weather penetrating your layers and soaking you ‘to the skin’, which then increases heat loss once again. Warm headwear prevents 47% of heat loss and gloves to keep your hands mobile. The wicking headwear made by Matt and Buff work well as a wicking layer for the head and neck in the right conditions, but once sodden by rain or sweat, they need to be replaced by thicker, warmer headwear.

Once on the hill
Once you or any of your party start to feel ‘chilled to the bone’, ‘frozen and shattered’, ‘shivering’ or ‘soaked to the skin’ you are in the first stages of hypothermia and it is absolutely vital to deal with this immediately. (This is the easiest stage to resolve and you will regret it if you don’t). Stop, rest, get out of the wind/rain, put on the correct clothing, drink water, eat something sweet and make sure your body warms up before deciding to continue or vary your route for safety reasons.

If walking with others who may be suffering, do not push on ahead and ignore them thinking they will cope or it will get better. This increases their despondency and accelerates their medical decline. Positive mental attitude (PMA) is a vital component in dealing with issues like this on the hills. Be supportive, ask questions and ensure they take on board water and sugar in some form. This can be difficult if dealing with children, or a group which wants to ‘press on’, but even more important for reasons stated above. Then make a decision to consider your best route options. Remember, the hills will still be there tomorrow!

If you ignore it
If a person is in a worst state than this, with a drunk like appearance, confused and argumentative you have to act very quickly and positively. They need to be out of the wind and rain, remove cold clothes next to the skin and put into one or two sleeping bags and if possible fed warm (not hot) sweet drinks. It used to be suggested a fully fit member of the party to get in the bag with them and act as a warming element, however this is now not considered the best policy.

The basic principle is to get shelter, get them dry, put them into one or two sleeping bags, keep them awake, cheer them up, get them to take on board sugar and liquid, and let their own shivering very gradually warm them up back to normal temperature. Of course you and the rest of the party are not going to be much use to them if you stand around getting colder and hypothermic as a result of this medical attention!

Emergency rescue
Weather conditions and the condition of the patient must decide your next course of action. Emergency rescue or not. So you must consider the best options for all. Either split the group to walk down to call for rescue or put up shelter/tent(s) if you have one, to keep you all and the patient warm, then call for emergency assistance, again splitting the group. (You must know how to call for rescue BEFORE you set out. Mobile phones cannot be relied upon).

Advanced hypothermia
If the person passes this stage they are in the danger zone of advanced hypothermia. Do all of the above, but you urgently need emergency rescue and we would advise you to always be aware of where you are, how close you are to assistance, how long it may take to get there and what you have in your rucksack to keep you and your party warm and dry. Bothy/bivvi bag etc.

For your consideration
There are various medical and Mountain Leadership courses run around the UK who can teach and advise how to deal with such emergency situations on the hill correctly. If you feel unsure about what you would do in this situation, we recommend attending. Prevention is better than cure! See any Outdoor Magazine for details.

Disclaimer and safety warning
All the information contained within this website, and associated media is for informational purposes only. The material does not constitute advice and you should not rely on any of the content to make any decision or action which may result in injury to yourself or a third party. In no event do we accept liability of any description, including negligence, for any damages or losses whatsoever resulting from the use of information contained within. 

On my 2005 TGO Crossing I was on day two of my walk across Scotland in very poor May conditions. I started at 6am after a poor nights sleep and it was still raining sleet. After 4 hours across the sodden mountains the weather hadn’t improved. Arriving at a field of peat hags some 1km wide, I remember thinking it looked like my idea of the Somme! Rusty long abandoned wire fences twisted and wove in and out of the many ditches and streams below a dark, moody grey misty sky.

This took almost 2 hours of slipping, sliding, falling, back tracking and getting angry at times knee deep in cold wet peat. By the time I reached the next obstacle, an 8 metre river, I realised hadn’t stopped all morning and had a brew or much to eat. The bothy at Maol-Bhuidhe was not too far away on the other side, so stripped off, put on my aqua shoes and stepped into the fast flowing torrent, which was thankfully just over knee deep.

I crossed quickly, but could feel the first effects of hypothermia kicking in with a vengeance. I was shivering so much and couldn’t feel my hands, so struggled to put my boots and clothes back on. Eventually, it could only have been minutes but felt like hours, I crawled up the slippery bank to the track, which after 1km took me to the bothy.

All the time my mind was thinking negative dark thoughts and feeling very low. I just couldn’t be bothered to eat any of the snacks in my pack, and I knew I really needed the shelter of the bothy as soon as possible.

Once inside I did all mentioned here. I removed my wet clothes and wrung them out, rubbed all the water off my body, had a hot chocolate drink, and put on my dry clothes, while waiting for the meal to cook. I felt I wasn't hungry, but forced it down all the same.

Once the warm food was inside me I started to think more rationally but it still took almost an hour and a half to fully recover.

Then, topped up correctly with food and warm drinks, I put my damp clammy clothes back on and continued feeling fine. Thank goodness for bothies!

Conclusion: Lesson learned! From that trip onwards, I have always kept a small bothy bag in my pack if I think the weather will be that changeable. Thankfully it doubles as a tent footprint and windshield, so is worth the few extra grammes.