Why Does Hot Tea Cool Down Faster When You Blow On It?

Imagine your hot tea is wearing a warm, invisible blanket made of steam. This blanket keeps the heat stuck inside the cup. When you blow on it, you are like a little wind machine that pushes this blanket away.

As the old, warm air moves away, cooler air from the room rushes in to take its place. Cool air touches the hot liquid and soaks up the heat very quickly. This keeps happening over and over again as you keep blowing.

There is another trick happening too. Some of the water in your tea turns into tiny droplets and floats away as steam. This process takes extra heat with it, leaving the remaining tea cooler. So, blowing does two things: it swaps warm air for cool air and helps some water escape to carry heat with it.