If the temperature outside reaches -40 degrees, most humans would die within 10 minutes of exposure.

Arica

The driest place on Earth is in Antarctica in an area called the Dry Valleys, which have seen no rain for nearly 2 million years. There is absolutely no precipitation in this region and it makes up a 4800 square kilometer region of almost no water, ice or snow.

Even though humans don’t typically go into torpor of their own volition—and our bodies typically prevent it by shivering—Drew explains that there’s no single “hibernation molecule” or organ that humans lack. In fact, torpor can be induced by doctors in extreme circumstances.

Hibernation, then, not only conserves energy, but may also be adaptive in slowing cellular aging14. Recent studies have found that more time spent in torpor can decelerate telomere attrition, or reduce cellular aging, among small hibernators23–25.

They generally use earplugs and a sleep mask to block out the noise and light. In the weightless environment of space, the carbon dioxide ( CO2 ) that astronauts expel could form a bubble around their head. That is why they have to sleep near an air vent.

Generally, the small hibernating mammals live longer and reproduce slower than small non-hibernating mammals. During hibernation, animals go into a low-energy state, basically sleeping through the winter in a safe place and surviving on the body’s fat stores.

It’s hard to say which animal hibernates the longest. A good choice would be edible dormice (Glis glis). They can hibernate for more than 11 months at a time. In one experiment, a brown bat (Eptesicus fuscus) hibernated in a refrigerator for 344 days.

One misconception about hibernation is that animals do not wake while hibernating. They do wake up, but how and how often they do depends on whether they are true hibernators or light sleep hibernators, Russell said. Light sleep hibernators wake more often throughout winter and carry on as usual while they are awake.

Never poke a bear—especially one that’s hibernating. It’s important to avoid other resting animals, too. Waking these critters can be very bad for them. They need to save their energy.

Females fast throughout hibernation. They may lose most or all of their fat stores. Unlike most other hibernators, female polar bears give birth while hibernating.

Grizzly bears and black bears generally do not eat, drink, defecate, or urinate during hibernation. Bears live off of a layer of fat built up during the summer and fall months prior to hibernation. Waste products are produced, however, instead of disposing of their metabolic waste, bears recycle it.