Hallucination, amnesia, frozen extremities: What happens to your body at -20C?

I woke up this morning and couldn’t leave my bed. The heating was on overnight, a move to make dads everywhere turn mauve with anger (“Why do you need HEAT if you’re ASLEEP?”), and yet, despite my laissez-faire approach to energy consumption, it was still so cold that I had to sprint to the shower.

Like so many of you, as hot water hit my face and snapped me from my cryogenic stupor, I wondered: what would happen if this never stopped? Or worse… what if it just kept on getting colder? Colder and colder and colder. What would happen then?

Well, death, obviously, but what about in the run up? The journey is sometimes more important than the destination, and let me tell you, it’s a thoroughly miserable journey.

Here’s how the hypothetical ice apocalypse pans out working our way from “brrrr it’s a little bit chilly, innit?” to “here lies humanity, frozen and shattered into a million pieces”.

Below 10°C, your body vasoconstricts, meaning your blood vessels begin to narrow. This reduces blood flow under the skin. If those vessels constrict too much they’ll eventually burst like jam-filled doughnuts, leaving you with a red face. Which is why so many Soviet Russians in films look like your alcoholic uncle. It’s not just vodka that does that to your face, no, cold does that, too. It also plays havoc with your fingers and toes, hands and feet, your ears, your nose, and your penis (but you already knew that). This is the blood being drawn away from your extremities and back up towards your core, where all the important stuff lives. It isn’t life threatening, but is uncomfortable.

Below 5°C, your nose starts to run as it goes into panic mode, desperately over-moisturising itself with snot. The cold and dry air is having an absolute field day with your lungs. By now you’ve started shivering (also known as oscillatory muscular activity). Shamefully, your own body no longer trusts you to keep your muscles warm and starts physically shaking you to jolt them back into life.

As the weather drops still further and the temperature tiptoes below zero, that’s when things start to get a little grave. The wind chill factor can magnify the cold and make you feel like things are ten times worse than they are, and things get even bleaker if its raining, seeing as your body transfers heat energy twenty-five times quicker when wet.

At -2°C, beer starts to freeze, rendering even your tried and tested lager-jacket obsolete. At least you can switch to wine.

At -5°C, the roads are scientifically-recognised death traps. Gritting lorries, unable to work at temperatures this low, are now just giant, skidding menaces, and their grit is useless.

At -6°C, your wine freezes, too. Plants also start to enter their final days. Usually able to protect themselves from The Cold Doom each winter by concentrating solutes like sucralose to depress the freezing point inside their cells, this age old tactic of Mother Nature ceases to be effective. The water in their cells will eventually begin freezing into crystals that puncture and destroy the plant from within. Imagine if John Hurt in Alien was actually a lovely tulip, and the alien was horrible ice. That’s what’s happening. So that’s food screwed, then, as no plants means way less meat as there’s nothing for the animals at the lower end of the food chain to eat, creating a slow domino effect of starvation. You might be okay, though. You’ve probably got a few tins of baked beans kicking around that you can ration. That’ll probably save you for a little bit.

So you’re hungry and cold. Your interior body temperature is usually around 37°C and when it drops… Ooh, boy. Hypothermia absolutely does not mess around. While scientists still cannot predict exactly how quickly you will die from hypothermia (or even how cold it has to be before you get it), let’s just say that you’ve got it, because it’s extremely cold at this point and you’re probably wet through after navigating a blizzard in search of a decent meal that isn’t beans.

As the outside temperature drops your interior temperature will start to as well: as you shiver and stamp your way to warmth, you will sweat, which cools on your skin (because it’s freezing cold) and lowers your body temp. Just a single drop in temperature (down to 36°C) and your muscles start seizing up. Known as “pre-shivering muscle tone”, this is cramp on polar explorer levels.

And then you start shivering. Properly shivering. One more notch down in your body’s thermometer and you’re a wreck, shaking uncontrollably, an uncoordinated mess of a human doomed to shake and shake and shake, wasting precious energy as your body sends extra blood to your convulsing muscles. This is bad news, and your lack of concentration means that you probably can’t do anything about it, because you’re going into shock. And with every further one-degree drop in your body temperature, your cerebral metabolic rate falls by about 5 percent, meaning that you are literally being frozen stupid.

“One more notch down in your body’s thermometer and you’re a wreck, shaking uncontrollably, an uncoordinated mess of a human doomed to shake and shake and shake…”

The temperature is still dropping. Say it’s -10°C: now the roads are closed, the everyday booze you once knew and loved is frozen solid, and there are probably widespread power outages as those left desperately gobble up heat and electricity leading to overloads down at the ol’ energy HQ. That’s presuming that people have even made it into the office to monitor that shit down at the power plant. The legal minimum temperature in an office is 16°C before you can go home and it’s safe to say that ship has sailed. Supermarkets are empty because deliveries have stopped and British trains have failed, too. Our transport infrastructure can barely survive a light dusting of snow anyway, but at -10°C, the cost-cutting 1920s electrified third rail on our railways will likely cease to work. No food, no transport, no nothing.

Oh, and now, because your power is out, your house is freezing cold, so your taps will be frozen, which means no water, hot or otherwise. And your pets have probably died. Which is horrible.

-15°C and, if you’ve survived this long, fair play. But things are, somehow, going to get worse. Let’s say your hypothermia, once “bad”, has now gotten pretty severe. At 33°C, your body has slowed your body down to near hibernation (and not the woozy fun kind Thumper did in Bambi): even though you know death is on the way, you can’t help but get really, really sleepy.

Now it’s -20°C, you’re six degrees below your regular body temperature and your breathing is badly affected, starving your brain of much needed oxygen, leaving you in a groggy fugue state something like a very, very cold amnesia. While you will now have forgotten all those embarrassing memories of Freshers’ Week, you’ll likely not remember how to do anything at all. You’ll need to piss very badly, though. Your kidneys are working overtime to process the fluid overload as all the blood in your body rushes to the centre, so the only thing you can feel right now is the desperate need to urinate. Pissing yourself might help here, but it will be but a momentary respite before frostbite.

Talking of frostbite, actually, it’s also a pretty fair to presume that your extremities have discoloured if not completely given up the ghost. After your presumably exposed fingers and nose, you can kiss your precious, precious penis goodbye.

As the temperature drops still further, and your body hits 30°C, you’ll be hallucinating. This is not the fun kind posh couples do on holiday, ayahuasca-ing their way to enlightenment, but more like your brain frying itself inside your skull. Also, your fingers and toes will probably be thinking about falling off at this point. You will have no idea where you are, how you got there, or what is going on, staring at your deadened digits. You’d be so out of it, that even if your mum came to save you at this point you would not recognise her. Even if your penis hasn’t fallen off, you’ll still be covered in urine and half-asleep and cycling between excruciating pain and feeling absolutely nothing, starving hungry while manically laughing at the frozen tundra of your living room.

Just another half-a-degree lower, at 29.5°C inside your bod, and, you’re wide awake and wanna get naked, throwing your soiled clothes off your highly alarmed, probably-a-bit-blue body. This is called “paradoxical undressing”, which happens when your hypothalamus—an almond-sized thermostat which keeps your interior temperatures in check—freaks out and fills your entire body full of panicked heat, making you feel like you’re on fire.

Then you pass out and likely crawl into a very small space, a defense mechanism known as “terminal burrowing”, to lay down and… well, not quite die. Not yet, anyway. First, you’ll just freeze pretty much entirely solid, unable to move. And then maybe if someone comes and finds you, they’ll be able to very slowly defrost you and hope that you’ll survive.

It can be done, this kind of extreme defrosting, as hypothermia actually, perversely, comes to the rescue, slowing your pulse and your breathing down so much that you’re left on standby until someone comes to your aid. But, since everyone else in the city is also frozen solid at this point, giggling like hyenas and naked as the day they were born, let’s just call this bit game over because nobody is coming for you.

On a brighter note, the weather is supposed to pick up a bit next week.

(Main Image: 20th Century Fox)

If you do see someone sleeping rough and stuck outside in this bad weather, read our guide on what to do and how to help.