For those who are not aware.
Fans do not cool the air, however, the stream of air does evaporate the moisture on the skin. In doing so energy/heat is removed from the body, thus fans do cool the body, especially if one is sweating.
For this reason, removing the sweat from your skin, say with a towel, actually reduces the cooling effect on the body.
Fans should not be left running when no one is present. The motor gets hot when running and thus increases, although only minimally, the temperature of the room