The Physics of Cooling Evaporation

Think about what happens when you get out of the bath or swimming pool. You feel cooler because your body is wet. Wonder why? It is evaporation on your skin that creates a cooling effect. When water or sweat evaporate from the surface of your skin, it removes excess heat and cools you. This is actually due to a principle in physics which goes like this. To convert water from a liquid to a vapor, it takes a certain amount of heat called the "heat of vaporization." This heat energy increases the speed of the water molecules so that they can escape into the air as vapor. As the heat is utilized to create vapor, a cooling effect is left behind.