Perspiration (Sweat)

body science · cooling system · mammals

Why we sweat. Your body sweats to release heat and keep your temperature just right, like a built-in air conditioner. When you exercise or it's hot outside, sweat comes out through millions of tiny holes in your skin called pores.

Sweat has salt. Sweat isn't just water, it also contains salt and other minerals your body needs. That's why you might taste salt on your lips after playing sports or running around.

Babies and sweat. Babies are born with sweat glands all over their body, but they don't start working well until a few weeks after birth. This is one reason newborns need to stay at the right temperature.

All mammals sweat. All mammals have sweat glands, though some animals like dogs and cats have very few on their skin and cool down other ways instead. Horses and humans are champions at sweating to stay cool.