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Why do hot drinks get cold when you blow on them? |
Everyday Marvels
Have you ever had a steaming cup of hot chocolate that’s just too hot to drink? The hot chocolate is giving off a lot of heat and trying to cool down by letting the heat escape into the air, but there’s just one problem. The hot chocolate has heated the air above the mug that contains it. A warm cushion of air above the mug won’t cool the hot chocolate as quickly as cold air.
There is a pretty simple solution! If we blow that cushion of warm air away, cool air will take its place and cool the hot chocolate faster. The air above the mug will soon get warm again, but then we just need to take another deep breath and blow it away!
Always be careful with hot drinks though. Sometimes they are just too hot to drink, and you don’t want to risk burning your mouth or your tongue.
Wind Chill!
On really warm days, a nice breeze can help us feel cool. On really cold days, a breeze can make us feel too cold and make us want to run inside.
When people talk about wind chill, they’re talking about how cold it feels outside because of the blowing wind. Wind makes the temperature feel cooler than it actually is!
Why do you think the wind does that? The next time you’re outside and there is a breeze, hold your hand up to face the wind. Which side of your hand feels cooler? What about the moving air makes your body feel cool? Is it similar to how hot chocolate cools down when we blow on it?