When it's Too Hot for a Fan

When indoor air temperatures are cooler than about 95 °F:

Use a fan when outdoor air temperatures are cooler than indoor air temperatures. (Fans in windows can blow cooler air into a room from outside).

Fans do not cool the air, so air currents flowing over the body must be cooler than your body temperature to cool you down.

When indoor air temperatures are hotter than about 95 °F:

Fan use may cause your body to gain heat instead of lose it. On very hot, humid days, sweat evaporates off the skin slower than normal, and fans make it even more difficult for the body to lose heat by sweating. It’s important to stay hydrated and follow other tips to get cool.