Why don’t penguins’ feet freeze? – video

Here at How It Works, we’re fans of cold, hard scientific facts and none of them are as cold or as hard as the icy rocks that your average penguin has to stand on for most of its frosty little life. In our new video, discover the clever tricks these cute creatures use to stay warm in frozen Antarctica.

This video is brought to you in association with Cubs 100. Visit the website to discover all the fun taking place this year to celebrate one hundred years of Cub Scouts.

Penguins like to live down south in the southern hemisphere but particularly in Antarctica, the frozen continent at the bottom of Earth where temperatures can often drop to 63 degrees centigrade below zero.

With temperatures colder than a polar bear eating an ice-cream in a blizzard, how do penguins keep their feet warm?

Nope, sorry. Socks are out as penguins use their bare feet to walk without slipping and to help steer them when swimming.

Plus they’d struggle to put them on as, y’know, penguins don’t have hands…

Thankfully penguins do have a few tricks to ensure their feet don’t turn blue and fall off. The first involves hunching down so that the feathers on their bellies cover their feet and help keep them toasty.

The second involves rocking backwards onto their heels to give their feet a break from touching the freezing ice. However, the final trick they have up their sleeves (or in their feathers) is really clever…

Penguins can adjust the flow of warm blood from their hearts into their feet. On cold days they let less warm blood through, so their feet stay just above freezing. On warmer days they let more warm blood through so that they can cool down.

You see, the arteries that flow from the heart to the feet are very close to the ones that flow from the feet back to the heart, so heat is easily transferred from one to the other, keeping the penguins feet just above freezing.

It’s called “counter-current heat exchange” and, believe it or not, humans can do this too! That’s why your hands turn whiter on a cold day as your body sends them less warm blood, so the rest of you is kept warmer!

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