Victims of exposure and hypothermia never have a good time of it, but sometimes they engage in a behavior that's both understandable and horrifying. It's called "terminal burrowing behavior," and involves losing their minds, running away, and crawling into a hole to die.
In the winter of 1847, the Donner Party was stuck, starving and freezing, in the Sierra Nevada mountains. A group of the stronger individuals braved the snow in the mountains, moving on along the route the entire party had hoped to travel, hoping to make contact with people over the mountains and send back a rescue party.
The group did not make good progress. Disaster after disaster beset them, including unusually strong blizzards and the loss of their only hatchet, which came apart while a member of the group was chopping wood. At that point, the group was not only starving, but freezing as well. They joined their blankets together to form a tent which would keep in body heat and keep out snow, but for one member of the group that wasn't enough.
Patrick Dolan had been weakening for days, and on the first night without fire, he started raving. Muttering incoherently, he stripped out of some of his tattered clothes, and ran out of the make-shift tent into the still-falling snow. The group was too weak to go after him, but a few hours later, when he wandered near to the tent, the men of the group went out to reason with him. It didn't work. They had to drag him, screaming and nearly naked, back into the tent. He died later that night.
Between 1978 and 1994, a survey of cases of death by hypothermia turned up only 69 clear results. The deaths were roughly evenly split between outdoor and indoor deaths. In2 5% of the cases, the description of the bodies list that they were either partially undressed or fully naked. Overall, the victims began taking off the clothes on the lower half of their body – taking off pants and shoes before going on to their shirts and jackets. When outdoors, the clothes formed a rough trail behind the body. As people froze, and took off their clothes, they kept walking.
Then they did something rather strange. In 14 of the 17 cases that included undressing, the bodies were found in positions that seemed like they were trying to squeeze into tight, low spaces. One woman, who had overdosed on an anti-anxiety medication on a cold night, was found partially under her own car. Other people would be found in attitudes that suggested they were digging into the ground or the snow. They would be under logs, or in shelves of rocks. People who froze to death indoors would be found in shelves, or under tables or desks.
It may sound like the person was searching for shelter so they could get a little heat, but the fact that the bodies were found naked – or nearly so – indicates some other motive. People in the final stages of hypothermia engage in "paradoxical undressing" because, as they lose rationality and their nerves are damaged, they feel incredibly, irrationally hot. They strip off their clothes to cool themselves down as they are freezing to death. Exactly why they then squeeze themselves into the tightest, lowest space they can find is still undetermined.
There's no ethical way to check the victims' motivations. Paradoxical undressing and terminal burrowing occur in the final stage of hypothermia. To try to replicate the conditions in a lab would be dangerous. Even if it could be managed, the behavior only shows up in about a quarter of the known cases.
So we're left with an eerie, sad pattern of behavior. As people succumb to the cold, they tend to run – away from their present location and away from companions who might help them. They go out into the cold, stripping as they move. And when they finally feel the end coming, they try to find some quiet, hidden spot to die.