How to

18 May 2016

Breakdown: What Happens to Your Body as Cold Sets In?

We’ve all experienced cold weather, and we all know how uncomfortable it can be. Your hands seize up, your nose starts to run, your breath fogs up, and so on. As the temperature dips below freezing, these curiosities and mild annoyances become more serious, and eventually they become life threatening, if you aren’t dressed or prepared appropriately.

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What actually happens to your body as this process advances though? Well, it works in stages, the first being your body actively attempting to conserve energy, and the second being it going into panic mode, unable to cope with the decreasing temperature. Here’s a look at the different ways your body reacts, and the science behind them.

Hands Seizing Up

This rather unpleasant feeling is one of the first things to occur when you step out into low temperatures, but it’s actually a good thing. In order to conserve heat energy, the blood vessels will constrict in order to reduce flow. This means that blood which would otherwise be moving to the surface of your skin is moving further inwards instead. The side effect of this is that your fingers (and toes) will begin to seize up, as there’s far less blood warming them. Not fun, but a whole lot better than the same thing happening to your vital organs.


This is one of the earliest significant warning signs that you’re too cold. If the reduction of blood flow isn’t enough to stave off the cold, you’re going to start shivering. It’s an attempt by the body to generate more heat to warm itself. In the early stages it’s not that big of an issue, and you can always try other ways of maintaining constant movement, like jumping up and down or jogging on the spot to take over the job and stop it, but once it becomes completely uncontrollable, it’s a warning sign that you’re in danger of getting hypothermic. Once hypothermia fully sets in though, you stop shivering, so don’t mistake that for a sign that you’re starting to recover.

A Dulled/Confused State

If shivering doesn’t work, your body will start to try other, more extreme methods of conserving heat. At this stage, you effectively enter a state of torpor, as body function is reduced as much as it can be whilst still keeping you conscious. You drift into a stupor, less capable of performing even the simplest tasks, and are far more susceptible to confusion and forgetfulness. Your oxygen consumption will start to lower, which will make you tired, and if this is allowed to intensify further still, you’ll even start to hallucinate.


This is a separate, but equally severe effect which can be avoided so long as you keep your skin covered, particularly your hands. As previously mentioned, in colder weather blood vessels constrict, reducing flow to the outer extremities, and you feel it in your fingers first. If it’s cold enough the flow reduces so dramatically that skin tissue actually starts to die off, allowing ice crystals to form beneath the skin.

The early onset of this effect is known as ‘frostnip’, and is characterised by itching and pain, and then a yellowing or reddening of the skin. At that level, it’s unlikely to cause any long term damage, but if it’s allowed to progress the skin will harden and start to blister. At that level, it may lead to permanent loss of temperature sensitivity. Once you get to the third and fourth degrees the freezing actually descends into the deep tissue, freezing the muscles, blood vessels, tendons, everything. Movement and feeling go, the skin hardens dramatically, and if it’s allowed to carry on without being treated the affected areas could develop gangrene, or even drop off entirely. In short, do not get frostbite. It is the worst.

Paradoxical Undressing

Speaking of not getting frostbite, this is a really good way to get it. Once the coldness progresses to the point where your body is trying so hard to conserve heat that it completely frazzles your brain, an awful irony descends – you start to tear all your clothes off. This is a result of your hypothalamus – the temperature regulator for your body – going into panic mode and widening all your capillaries, causing a sudden flush. This burning feeling, combined with the brain’s already warped condition often causes people to rip all their clothes off and even crawl into a tight space, which is called terminal burrowing.

Loss of Consciousness

This is the final, often fatal result of extreme coldness. As your heart rate lowers, and your blood flow restricts itself further still, you will no longer have the energy to stay awake. Obviously if this happens then you’re in huge danger of actually dying from the cold. You have no line of defence left at this point and you’re likely completely exposed to the elements, your only hope is that someone finds you before it’s too late.

Callum Davies

Callum is a film school graduate who is now making a name for himself as a journalist and content writer. His vices include flat whites and 90s hip-hop.