It's summertime, it's hot, and you're sweating! Sweating is one way your body cools itself. As sweat evaporates, it cools you down.

Sweat is a liquid made of water and salt. Some of the water molecules in your sweat have enough energy to break free and become water vapor, or gas. This is called evaporation. For evaporation to happen, the air around you must be able to hold more water molecules.