Where is the wind coming from?Moisten your finger and hold it straight up in the air. Youwill notice at once that one side of the finger is cold. This is the direction from which the wind is coming. Heat is used up when a liquid vaporises or evaporates. The wind accelerates the evaporation of the moisture on the finger and you will notice even with a weak air current the greater heat loss on the side facing the wind. Anybody who keeps on a wet bathing costume after a swim will shiver even in the heat. The water takes heat from the body as it evaporates.