(0:00) Tugg: How come - how come hot air get cold when fan? 

(0:04) Hank: Hot air does not get cold when fan. Hot air, same hot when fan. But more air when fan. So heat is going to be carried away from your body in a couple of ways by air.

One is that you heat up the air that is near your skin like your skin is in contact with those molecules and they take some of that energy away, and then they're like close to your skin and they can be moved away. Or also more of them can be touching you because there's wind. So a big way is that you heat up the air near your skin and that actually gets replaced by new air when there's a fan or when there's wind.

Second, you also cool down because there's going to be a little bit of sweat especially if you're - it's warm out. So like little tiny amount of water on your skin and when that evaporates that also cools you down. And evaporation is increased when more air molecules are moving past your skin and thus more water molecules can evaporate into that air.

And now you know!