This article on surviving extreme cold is part of the Science in Sci-fi, Fact in Fantasy blog series. Each week, we tackle medical or technical aspects of science fiction or a historical / world-building topic of fantasy with input from an expert. Please join the mailing list to be notified every time new content is posted.
The Expert: Gideon P. Smith
Gideon P. Smith, MD PhD MPH is a physician-scientist. In an earlier career, he was a geophysicist. In fact, that is what the PhD is in. He spent several seasons working in Antarctica, planting seismometers while tracking whales with the marine biologists on board research cruises in the Drake Passage. He has published over 100 first and senior-author papers in scientific journals including in top-tier journals such as Science. In his spare time, he writes science fiction and epic fantasy and has written for the Science Fiction and Fantasy Writers Association and Black Hare Press. You should check out his blog and maybe follow him on Twitter.
Surviving Extreme Cold for Writers, Part 3: Physiology
In part 1 of this three-part article, we dealt with the social and evolutionary aspects of cold environments.
In this 3rd and final part, we will look at the physiology of cold. We will look at what cold does to humans, such as hypothermia, and frostbite, and the onset and healing of this.
And once again we will look at how these things are often misrepresented in science fiction, and how we might go about getting it right. But first, In order to understand what is wrong in science fiction with the way cold exposure injury is portrayed, we need to understand some facts about how cold affects us. And we also need to bust some of the common myths that trip writers up.
Myth 1: Frostbite or cold injury happens at a certain temperature, and starts in the fingers
Fact 1: Frostbite is as much determined by the person as by the temperature, and starts in exposed areas
Remember the basic definitions from part 2. Temperature is a measurable, quantifiable physical parameter. Cold is a sensation. When my house is 68F I feel unacceptably hot. My family feels this is cold so move the thermostat up to 76F.
You may think this is a minor point but from the perspective of understanding the effects of cold and its amelioration, it is an important starting point.
There is no one size fits all. Just as we perceive cold differently, our vulnerability to cold injury varies. So, coming to physiology, as I mentioned in my article on skin, skin is much more than just a barrier. It actually has many regulatory purposes. The blood vessels in the skin contract or dilate depending on whether our autonomic nervous system senses we need to conserve or shed heat. This effect is most prominent in the extremities, of which the fingers are just one.
The sweat glands activate or shut down within the skin based on this same factor, and the skin musculature which allows shivering, also helps thermoregulate. Our own body’s ability to activate these homeostasis mechanisms vary from one person to another. In addition, our body’s ability to retain heat is also affected by metabolism, the volume-to-surface-area ratio of our body, and our body fat density.
One of the most common areas people get frostbite is actually the face. Why? Because we use our hands a lot so we often realize they are stiffening up, that we are cold, and that we need to protect them, and usually we wear gloves. The face however is often exposed, but we are neither performing fine detail work with it, nor have the same density of nerves, and so while I certainly saw finger frostbite in Antarctica, I just as often, if not more often, saw cold injury to the cheeks, nose and ears.
Noses and ears have the same risk factor as fingers as they are at the periphery and the body’s homeostasis prioritizes heat in your core, shutting down peripheral circulation. This protects your vital organs such as the heart, kidneys etc, but leaves your periphery – toes, fingers, ears, and nose vulnerable. These areas also lack the ability to shiver.
Examples of Problematic Extreme Cold/Exposure. in Science Fiction/Fantasy:
Cold injuries are wrong
So in part 2, I picked a lot on Star Wars. I therefore in this article will pick instead on the other holy grail of pop-sci-fi, Star Trek. Here I’m thinking about the re-boot movie. When Kirk first crash lands on Delta Vega we see him climb out of the ice crater with his bare hands. However, later he is frozen just being in the environment. Before you get to actually freezing or frostbite, he strength and fine control in your hands will be lost. It is very unlikely he could have made that climb bare handed in real life.
Writers often also forget, or do not realize, that if their character is literally falling down from the cold, this will also affect their ability to critically think. Its not just their body, but their brain that will be affected in extreme circumstances.
Cold exhaustion without warning
In other scifi we see people end up with frostbite, or cold exhaustion with no warning. Or on the other end of the spectrum we see people experiencing agony on first cold exposure, or recovering completely after experiencing it. Part of the problem with frostbite is that it first numbs the skin, and so people feel cold but rarely feel the full impact till too late. Most of the pain comes on re-warming. Also, not every frostbite is the same. Frostbite has stages.
Stage 1 the skin is cold and painful, and red or purple. In stage II people will have a prolonged pins and needles sensation and the skin will peel in patches. Stage III they will have often permanent numbness as nerve damage has occurred, areas of skin will turn black and after a long time, break down or fall away. If you are going to give your hero stage III frostbite, remember these points:
- It will require prolonged cold exposure.
- There will likely be other symptoms of cold, and not just affecting the fingers
- Your hero will take a long time to recover and likely will have persistent neurological damage
If their fingers are black inside gloves, their exposed face will not look normal.
Ways to Get Cold Exposure Science Right in Fiction
Thinking about what we learned above, how can you get the science right, and what might be some cool things to include in your science fiction?
If you are going to give your heroes cold injuries recognize that they will experience most of the pain on re-heating. That there are stages to frostbite and it doesn’t happen quickly, and if it’s cold enough to occur inside gloves, it’s going to affect other body areas than just the hands. If they have stage III frostbite, the nerve damage may be permanent and healing takes weeks to months.
Also, remember that given each of us has different cold tolerances, that’s not just about ‘feeling cold’ it’s about vulnerability to cold injury. Some of your party will fare worse than others, in part based on height, weight, fat layers, whether they are accustomed to cold environments or not, their heritage, etc. Try and make logical choices about who succumbs and who does not.
Making it reflect reality can build in some potentially interesting plot elements. If cold-injury takes a long time to heal, warming their hands or rubbing them together is not going to enable them to suddenly perform fine motor skills. This is something that’s going to impact the plot, and potentially de-rail their entire original plan.
So that’s it for my attempt to summarize cold environments. When Dan originally asked me to write this article it was meant to be just a single 500 to 1500 word article. When I wrote it, it ended up 4000 words long, and thus had to be split. Believe it or not, I could say even more on this topic, but hopefully, this has thrown up at least some insights and new ideas.
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