Switching on a fan and feeling a nice breeze can feel very refreshing on a hot day, but what is going on? Is the fan taking some of the heat energy away? In a small, perfectly insulated room, switching on a fan can increase the temperature in the room as fans usually have a motor which gives out heat.
The reason why fans make you feel cool is due to something called the wind-chill effect. Blowing air over your skin causes quicker evaporation of sweat which allows your heat energy to escape much quicker than normal, making you feel cooler. Let’s hope we’ll be needing them soon!