Penguins spend months standing on freezing Antarctic ice. Not only they don’t have shoes, but their feet are not even covered in feathers or some kind of fluff. So how do they manage not to freeze their feet off? How can they stand not moving on the coldest ice on Earth without even worrying about their feet?
Most people wear socks all the time. That is just a normal part of life in those areas of the world that enjoy long periods of winter. But could you imagine standing with your bare feet on ice for months at a time? There is no doubt that penguins are adapted to this situation and they are not even stressing about it, but simple science of physics dictates that water freezes at 0 degrees Celsius and that is what penguins are mostly made of. But they do have one trick up their sleeves.
You may think that penguins need to increase the temperature of their feet to prevent frostbite. However, by warming their feet they would be losing valuable degrees of core temperature. It is a bit like your car’s engine. In order to not overheat (therefore, to be cooler) engine flows a liquid to a radiator, which takes and dissipates that heat.
If penguins were heating their feet, they would be getting colder. So instead they limit blood circulation in their feet and reduce their temperature to levels barely above freezing. In this way their feet remain cold, but their core temperature remains nice and cosy, thanks to a thick layer of fat, fluff and feathers. Heating feet would result in a loss of the core temperature, rendering all that insulation useless.
Because liquid contents in penguin feet become so low, they are pretty much immune to frostbite. Frostbite occurs when tiny crystals of ice start forming in your body, essentially tearing walls of cells apart. Penguins reduce amount of liquid and those crystals cannot form anymore. In fact, they even use their feet to elevate their eggs off the ice.
Interestingly, humans have a very similar mechanism. When temperatures drop to dangerous levels, our bodies go into a survival mode, which translates into maintaining the core temperature. That is why your hands become so cold and white – blood vessels contract restricting the blood flow and keeping more blood where it matters the most – in and round your vital organs. However, since we are not penguins and we are still mostly water, this does result in extreme pain, discomfort and even a risk of losing limbs. So get yourself some good warm gloves and winter shoes – you are not a penguin.