The Sweat System
Your built-in liquid air-conditioner
When you run around, you heat up like an engine â and switch on your built-in sprinkler system. Sweat is your body's liquid air-conditioner!
A sweat gland in the skin
Real anatomy picture coming soon
Real anatomy photo spot: a coiled sweat gland opening onto the skin's surface
Three million sprinklers
You have about three million sweat glands, most in the palms of your hands, the soles of your feet, and your forehead. When your brain senses you're getting too hot, it switches them on. Sweat spreads over your skin and evaporates â turning from liquid to gas â and that change carries heat away with it. That's evaporative cooling!
Why salty?
Ever taste sweat? It's salty because it's filtered from your blood, which carries salts. When you sweat a lot, you lose water and salt â that's why athletes drink special drinks after long games. Your sweat also cools you best in moving air â one more reason a breeze feels great after running.
Mr. Bones says: I'm a fictional skeleton, not a doctor! This is for learning and fun. If anything hurts, stop and tell a grown-up you trust.
