It’s a warm day, not a cloud in the sky. It’s the month of March on a isolated mountain in Ireland and the weather has been uncharacteristically warm for this time of the year. There is so much heat from the sun that you leave you warm clothes behind and don’t bring any food with you. It’s a warm day you’ll be up and down in no time.
After a four hour trek up to one of the summits, you spot a rocky outcrop that you decide will be a fun scramble. The is a beautiful scramble, just one little crux that you need to get across. A quick jump on to protruding foothold and you extend your hand to grab a very obvious handhold. As you switch balance and reach, the foothold snaps. The next thing you realise is that you are falling. You manage to land on your feet when you hear a snap. You try to stand up but pain shoots through your right ankle.
You are now immobilised alone on the top of a mountain. You sit on a rock berating yourself for being so stupid.
Sitting there you notice that it’s actually quite cold when you’re not moving. Searching through your small backpack for anything, you find nothing but your phone and a small bottle of Rum.
Hypothermia occurs when the body is unable to maintain normal temperatures because of exposure to cold. The body’s normal core temperature is between 36.5°C and 37.5°C.
Hyperthermia affects Hikers and armies alike.
The classical piece by Tchaikovsky, the 1812 Overture, commemorates the successful Russian defence against Napoleon’s invading army.

Hypothermia aided the destruction of the invading army by causing confusion, lost of consciousness and death. Others just fell to their knees and eventually died where they knelt.
As hikers, we may not be braving the severe Russian winters, but we are equally at risk of hypothermia. We are particularly at risk when temperatures are around freezing. Even in warmer temperature we can still be at risk. Simply being immobile on a mountain ridge at 10 °C in a storm can kill you. Windchill makes it worse by moving the warm air next to your skin away. Wet makes it worse. Water evaporates and cools. It also reduces the effectiveness of insulation. The combination is deadly. Skinny people are more susceptible than overweight people.
Not sure what to do, feeling the pain of the broken ankle, hoping someone will pass by, you decide to warm up by taking a couple swigs of rum. You now feel much warmer and more relaxed.
However, alcohol consumption increases the risk of hypothermia by increasing blood flow to the skin, resulting in heat being lost to the environment. This produces the effect of you feeling warm, when you are actually losing heat. Alcohol can also decrease the body’s ability to shiver and use energy that would normally aid the body in generating heat. The overall effects of alcohol leads to a decrease in body temperature and a decreased ability to generate body heat in response to cold environments.
The earliest stages, called mild hypothermia, are characterized by such things as a loss of coordination and changes in personality.
As the sun drops behind a far away peak, the temperatures plummets to around 7°C. You are feeling very cold and you’re core body temperature now drops below 34 °C, you now start to shiver. At this point, you still have the presence of mind to do things like make a phone call. You can temporarily stop the shivering to retrieve the phone and dial a number. But there is no reception, there are no network antennas in close proximity to even allow an emergency call.
As your temperature continues to fall below 34 °C, the shivering becomes uncontrollable.
The evening progress and you feel the cold. As you core body temperature falls to 32 °C, you are now having irrational thoughts, sluggish thinking, amnesia, and difficulty speaking. You know you are in a perilous situation, but you are feeling surprisingly calm. You have no real dread or any real pain or distress. Without that fear of death, the drive to take care of oneself is lost. At this point you know you should be doing something to save yourself but you can’t really be bothered.
As your body temperature drops below 32 °C,  you stop shivering. Now you feel really confused and start behaving more irrationally.
Once  shivering ceases you are in a life threatening situation and will very likely die if you do not get help.
Parts of your body will start to shut down, sending messages to the brain telling it that these areas are fine. Your brain doesn’t care anymore or simply doesn’t know that it’s cold.
You start to experience a behaviour called paradoxical undressing. You become disoriented, confused, and combative. You feel like your skin is too hot and burning and so start discarding your clothing, which, in turn, increases your rate of heat loss.
In severe hypothermia you can be quite serene, not frightened, or not even really alarmed. You know you are in trouble, but you have resigned yourself to it and are pretty calm.
You have been sitting here immobilised for several hours now while staring at a clear dark sky and the ambient temperature has now fallen to freezing.
Suddenly you hear a voice. Yes, it’s your friend, he’s calling. At last, and unbelievably, his hut is just 50 metres away hidden behind a boulder. Your friend helps you up and you now see his house, which is fully lit up. Opening the door, you are welcomed by a blazing open fire, your friend lays you down on a thick soft rug in front of the open fire. You begin to warm up and feel a great sense of relief and gratitude that the ordeal is over. The hut is beautifully decorated inside. Your friend is preparing a pasta dish and there is an opened bottle of red wine on the table. This was some ordeal but you sure will have some story to tell tomorrow. In the meantime you will need to get your ankle seen to and will have to make you way from your friends hut to your home. But those things can be taken care of tomorrow. Tonight, you are getting heat back into your body and are about to feast on a meal with wine.
The flames from the fire dance around the wood and then start changing form, the flames darken and get smaller, the interior of the hut starts to vanish. You call to your friend to ask what’s happening, suddenly you are alone staring at an empty sky.
With restricted blood flow to the brain, you have started to hallucinate. Your friend, the hut, the meal, the wine were only a illusions. You now become consumed with a sense of despondency of dying alone on the side of a mountain. Tears roll down your cheeks.
The despondency lasts for a while and then is replaced with a calm acceptance of your fate.
With your core body temperature below 29 °C,  you become unconscious. As the brain cools down, you experience a gradual decrease in your level of consciousness until you slip into a coma. After that, all of your metabolic processes start to slow down. As your body temperature drops below 26 °C, your heartbeat will become irregular and eventually stop. The moment of death will likely be silent and relatively painless.
A person dying from hypothermia will get into sort of a dreamlike state, drifting in and out of consciousness, and they may have visions of random things, possibly in a state of bliss. Dying from hypothermia is often perceived as a slow and painful death. It may be slow but by all accounts it’s not as painful as people believe.
The next day a walker finds your dead body and your death becomes another lesson and another statistic on how to dress for the outdoors.

This hypothetical account of hypothermia is based on my own experiences of mild hypothermia together with the research that I have done into the matter.