Frostbite — sometimes called cold burn — is an injury that occurs when a part of the body freezes. When it’s cold, the body reacts by constricting the blood vessels close to the skin. This keeps the warm blood in the body from losing heat to the air. But it also can leave the areas close to the skin in danger of freezing.
If the skin freezes, the tissue can die. Mildly frostbitten skin can look yellow or gray. It itches and hurts. As the skin freezes deeper, it might blister. With severe frostbite, the skin can become waxy in appearance as all the nerves, tendons and muscles freeze. Severely frostbitten limbs might need to be amputated — or even fall off on their own.
Frostbite most often affects the nose, cheeks, fingers and toes. The area that is freezing may go numb. Because of that, a person might not realize they are suffering from frostbite until someone else points it out.
In a sentence
A person may suffer from frostbite, but their pups won’t — dog paws have a special network of blood vessels to keep them warm.