ELI5: Why does fog feel cold?

Imagine you're running around outside and get a little sweaty. You feel cooler when the wind blows, right? Fog is a bit like that!

Fog is basically tiny, tiny water droplets floating in the air. These little droplets are already pretty cool, usually colder than your skin.

Here's why it feels cold:

• Water's Special Power: Water is good at taking away heat. Think about jumping into a pool - the water feels cold at first because it's taking the heat from your body.

• Evaporation: When the fog touches your skin, some of those tiny water droplets turn into a gas (evaporate). To turn into a gas, they need energy. Guess where they get that energy from? Your skin! Taking energy from your skin makes it feel colder.

• Lots of Little Droplets: Because there are so many tiny water droplets in fog, they can take away a lot of heat from your skin all at once.

• Already Cool Air: Fog usually forms when the air is already cool. So, the air around the fog is also taking heat away from you.