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Have you ever eaten ice cream too fast on a hot day and ended up with a bad headache? That’s sometimes called a brain freeze. It doesn’t mean that your brain is frozen, though. It just means your body and brain are trying to figure out what to do about all that icy cold stuff you just swallowed.

Touch your tongue to the top, or roof, of your mouth and slide it back toward your throat. You have a lot of nerves there that pick up sensations like touch or temperature and send messages to the brain about them. When very cold things touch that part of the mouth, it’s kind of a shock to your body. Some scientists think one of the important nerves there goes a little crazy with the cold and starts sending lots of messages to the brain. But the brain reads those messages as pain instead of cold. Another idea is that the cold makes more blood flow to the brain. That causes your blood vessels to expand, or get bigger. Before you have a chance to say “Brrrrr!” you get a brain freeze.

That extra blood means more pressure in the brain. Some scientists think that may be the reason people feel like they have a headache. Your body reacts by making the blood vessels contract (get narrow) to try to lower the pressure. Once that happens, the headache usually goes away pretty fast. Not everyone gets brain freezes, and scientists aren’t sure why. If you do get them, don’t worry. Brain freeze headaches aren’t dangerous. But next time, don’t eat your ice cream so fast!

Did you know that cats seem to get brain freeze too? Take a look