Sweat wets the skin, and when it evaporates, it cools the body.
Fig 4-23 sweat contains water, salt, lactic acid, vit.
Evaporation of water cools the body.
What cools the body?

1. evaporation
2. Putting heat on it
3. Movement of an air mass
4. Starting a fire
5. Evaporation of alcohol
6. Evaporation of water
7. vaporization
8. reduced heat