With low temperatures and food shortage, winter is a terrible season for animals. Many animals enter hibernation (冬眠) to get through it. Hibernation can help cool the animal's body and slow its heartbeat to just a few times per minute, for up to months at a time.
But why don't humans hibernate? Our body is not fit for hibernation. Humans have only migrated into temperate and subarctic areas (温带和北极地附近) in the last hundred thousand years or so. That's not quite long enough to evolve (进化) all the metabolic adaptations (代谢适应) we would need to hibernate, according to the BBC Science Focus magazine. For example, how to settle waste is a big challenge for human hibernation. Animals that hibernate are able to stop their defecation (排泄), and sometimes save energy by taking their waste. Unluckily, humans can't do this. There are other challenges. Body temperature below 2.8℃ may hurt human's stomach and cause pain. Cold temperature can also make people ill easily, according to Smith-sonian magazine.
In fact, humans don't need to sleep through winter. We can use fire, clothes, houses and food to help us live in the cold.
Could humans hibernate in the future? According to University of Oxford in the UK, being able to hibernate would make such long-time journey less boring and save important energy for the astronauts. It's likely for long-term space travel. From 2014, NASA has worked hard to do a research on it, for it will be a way to help develop long-term space travel, according to The Atlantic magazine.
