Why do we sweat?

On Saturday at noon, Na played shuttlecock with friends in the alley outside her house. Soon her forehead was beaded with sweat and the back of her shirt was soaked.

Cú Bông guessed that sweating is the body pushing out dirt. So the more you sweat, the cleaner you get.

Indoors, Na sat by the fan; as her damp shirt dried, she felt cool, even a bit chilly. Mum handed her a glass of water: “When you sweat a lot, you need to drink.” If sweat only got rid of dirt, why would hot days and hard play make more of it?

The main job of sweat is to keep the body from getting too hot. When the body warms up, sweat glands in the skin start making sweat. Sweat is almost all water, with a little salt and a few other things.

As sweat evaporates from the skin, the skin cools down. That is why Na cooled off fast in front of the fan while her shirt was still damp. Sweating a lot also means losing a lot of water, so you need to drink to make it up.

Step through to see how sweat cools the body. At which step does the skin start to cool?

When the body warms up, we sweat; as the sweat evaporates from the skin, we cool down. If you sweat a lot, remember to drink enough water.