On a warm skin water evaporates; i.e., it is converted from liquid to gaseous state. In this process, the skin loses some of its heat; as a result, the surface of the skin is cooled. This process is known as ‘evaporative cooling’. Our body also uses this effect to regulate the body temperature when it is hot. It secretes sweat, which evaporates, and thus cools down the skin. We can also cool the cold drinks in this way while camping by wrapping the bottle in a wet cloth and placing it in wind.
