If you’re anything like me, you’ll have spent the national lockdown in November staring listlessly at the wall (or the ceiling), wondering how many hours there are left before it’s acceptable to say “I’m going to bed”.
Even though I was physically awake, mentally, I felt I may as well have been hibernating.
All sorts of other animals hibernate. Bears are probably the most well-known, but hedgehogs, echidnas and bumblebees also burrow underground to wait out the bleakest months of the year. So why don’t we?
The primary reason that animals hibernate is to avoid the cold. Keeping warm at a time when the weather is harsh and food sources are in short supply requires a huge amount of energy. Animals can instead preserve energy by entering a state of metabolic depression – in which their breathing and heart rates slow down.
All three major subclasses of mammals (monotremes, marsupials and placentals) contain species which hibernate. And there is evidence that hibernation techniques are tens of millions of years old. So that means there is a high likelihood that some of the animals from which humans are descended could hibernate.
Personally, it seems unfortunate that we can’t. Our hearts cannot function outside of a small temperature window. Below 28℃, human hearts fail because they cannot remove excess calcium. At 35-40℃, human cells start to collapse and die.
Humans evolved in tropical Africa, where seasons are not so marked and food supply is fairly constant year-round. This might explain why we do not have the biological ability to hibernate. There is also evidence to suggest that hibernation reduces memory retention — so it should only be used if it’s impossible to survive otherwise.
However, the main reason we don’t hibernate is likely to be that the discovery of fire, hunting, shelter building and agriculture meant we were able to overcome cold weather conditions whilst still remaining active all year.
But although our ancestors did not need hibernation techniques for survival in the past, they might help people survive in the future.
Doctors can induce torpor in emergency cases where operations require the heart to be stopped. It is thought that cooling the body temperature of sedated patients decreases inflammatory processes and thus minimises lasting damage to the heart — like an ice pack decreases swelling in a sprained ankle.
In the future, inducing “hibernation” through cooling might save trauma patients whose hearts have stopped beating, buying time for doctors to perform surgery. This would be a game-changer in conflict zones or rural areas, where surgery may not be immediately available.
Scientists at NASA are taking this idea even further, hoping that hibernation can benefit space travel. Astronauts have to do physical exercise for 6 hours a day when in space, to prevent their muscles from breaking down. If they could hibernate, they wouldn’t need to do this.
Not only would they spend less time exercising, astronauts would also need less to eat. Hibernation could allow humans to travel much further in space — to Mars perhaps?
But for now, this research is very much in its infancy. And because hibernation, unlike sleep, is detrimental to memory retention, it doesn’t seem to be the best solution for my winter blues. I’ll guess I’ll stick with coffee.
Image: Anna Main