When water changes phases from liquid into a gas it sucks a lot of energy into it. This is how sweat works to cool you. The water comes in, cools things through

When water changes phases from liquid into a gas it sucks a lot of energy into it. This is how sweat works to cool you. The water comes in, cools things through conduction (think liquid cooling in a computer) and then they evaporate it and it sucks a bunch of heat. It is then in the air and becomes rain eventually.