Fact 1: Sweat wets the skin, and when it evaporates, it cools the body.

Fact 2: Normally, the body cools itself by sweating.

Given the two facts above, answer the question "The body cools itself when wetness evaporates from what?" with the following options: 
- skin
 - H 2 O
 - CO 2
 - eyes
 - follicles
 - H20
 - hair
 - heat


 

 skin        