You might expect that someone in danger of freezing to death would want to be wearing as many clothes as possible, but somewhere between one in five people and a half of all those who die of hypothermia actually start to strip down before they die. This phenomenon is known as 'paradoxical undressing'. Many are found completely naked, often curled up in the closest thing they could find to a cave. Nobody really knows why, since people hardly ever freeze to death while scientists are watching, unless the scientists are freezing to death too.
Our bodies are better at registering that a temperature is extreme than they are at saying whether it is hot or cold, which must be a factor here. Most people who are in the process of freezing to death surely know they are cold, though - even in the confusion of hypothermia, even compounded by the effects of alcohol or other drugs, which are involved in many but not all of these cases. We must look deeper.
The most popular theory is that it is to do with muscles getting tired out. When the body is exposed to the cold, it reacts by contracting blood vessels close to the skin's surface - this vasoconstriction reduces the heat lost from warm blood as it is pumped through cold flesh, which helps explain why our extremities go numb and lifeless in the cold. If the muscles constricting those blood vessels finally get worn out, it would make sense that the blood would come coursing back through the veins. With hot blood suddenly making it through to their chilled limbs, the freezing person might suddenly feel overwhelmingly hot.
It has also been speculated that paradoxical undressing may be the result of a malfunctioning hypothalamus, which regulates the body's temperature responses, probably also leading to vasodilation. However, I have not been able to find any detailed description of the mechanisms that might be involved.
Most cases of paradoxical undressing are also associated with terminal burrowing behaviour, or 'hide-and-die syndrome'. Having stripped off, the dying person crawls into a nearby enclosed space - under a bed or a hedgerow, say, or inside a wardrobe - where they curl up and await the end. This is even more mysterious than the undressing itself. Perhaps the cold triggers some kind of vestigial hibernation instinct; perhaps such enclosed spaces just seem comforting, in some primordial way. Delirium may be involved.
Whatever the explanation for the undressing and the burrowing behaviour, they are often greatly disconcerting for anyone investigating hypothermia deaths. If you don't know that these things are very common in cases of terminal hypothermia, you are likely to assume that the nudity is the result of a sexual assault, and the 'hiding' of the body has been done by a murderer ineffectually trying to cover their tracks. Often the victim's clothes are found in a trail somewhere behind them. Sometimes they manage to keep on going for a long time after disrobing, and their naked body is found exposed a mile or more away from a pile of their discarded clothes, leaving endless fuel for speculation about their final hours. Sometimes it gets even stranger than that.
More
- Fortean Times: 'Cold Cases'
- "Terminal burrowing behaviour"--a phenomenon of lethal hypothermia
- "Paradoxical Undressing" in Fatal Hypothermia