Humans and hibernation: 4 reasons we don’t sleep through winter

1. We’ve got Sainsbury's
   1. Going into hibernation (the technical name for the state is ‘torpor’) is a bit like going into deep standby mode - an animal’s body temperature drops, their metabolic rate decreases massively, their bodily functions reduce to a minimum and they rely on fat stores for energy. It’s usually a winter activity, as those cold months are when their food is in short supply. But humans don’t really have this issue - although the type of food available in winter might be slightly different to what we can get in summer, there’s no shortage. We can always just pop to the supermarket to stock up on staples. And that’s a much simpler and quicker activity than basically voluntarily going into a coma for several months.
2. We’re not on anybody’s menu
   1. When food is scarce, smaller creatures have the added worry of becoming a desperate hunter’s dinner - bigger animals get a lot less picky about their prey during winter when there’s not as much choice on the menu. Hunkering down in a state of hibernation means being hidden out of sight and out of harm’s way. The process of bodily shutdown also stops animals from emitting any odours that could give their whereabouts away to hungry predators lurking nearby. Again, this just isn’t a problem that humans have. Being at the top of the food chain means that we don’t need to go into a state of suspended animation to avoid being someone’s main course.
3. We’d probably end up dead
   1. When the temperature drops, so does our heart rate, and if it drops low enough our hearts stop altogether. Why? Cold temperatures cause a calcium build-up which can lead to cardiac arrest - a heart attack. But our animal friends don’t have this problem. Their bodies have special pumps that remove the excess calcium, so their hearts can continue to function even in low-temperature hibernation mode when their organ temperatures drop as low as 1°C. We’d be in trouble around the 28°C mark. 
4. We just don’t know how to do it
   1. Plenty of scientists and researchers are trying to work out if it might be possible to put humans into a state of torpor - it could be useful for medical purposes, or for longer-term space exploration, etc. But at the moment they’re not getting very far. We just don't know yet exactly how animals start the process of hibernation, or how they keep it going. It’s possible that it’s triggered in a slow ‘bottom-up’ fashion, starting with small changes in individual cells of the body at a molecular level. But it also seems likely that higher level signals from the nervous system or hormones play a role as well. We’re sure to find the answers someday, but for now, we’ll have to stick with onesies, hot water bottles and lots of tea to get us through the winter months.