Imagine if you lived in Antarctica and had to stand barefoot on the ice all day, every day. How long would it be before your feet would completely freeze? We doubt you’d get by longer than several minutes, but penguins can do it for two months if needed.
With temperatures dropping to around -75 degrees Fahrenheit (-60 Celsius), watching penguins stand on the ice with naked feet looks painful. Luckily, they have special circulation that allows them to do it without freezing. We imagine they’re not exactly warm, but it’s something.
Penguin feet have evolved to survive cold weather over time. Their legs don’t require much heat to keep working. Their feet restrict blood flow when it’s really cold and keep the temperature just above freezing point so they don’t lose body heat through them. With the ability to regulate where they store heat, penguins are able to keep their eggs warm so they can hatch.
A similar thing happens to humans, it’s just not as extreme. You’ve noticed how your hands and feet get cold in the winter weather; this is because the blood gets redirected to the core of your body, to your vital organs.