because back the - 50 years ago-the world wasn't as trashy as it is now and we need to be taking earth day seriously now because we are destroying our world with pollution,plastic, and lettering like thoughing things out your car is awful.
This used use to transfer heat which is dissipated from the body. it is the heat needed to stabilize the body temperature for the cells and tissues to do some biological work.It is also from the heat that enzymes maintain there activity.