Why You Get Brain Freeze from Shaved Ice - The Science of Ice Cream Headaches

What That Sharp Pain Really Is

When you gulp down shaved ice all at once, you get a sharp, stabbing pain around your temples and forehead. This phenomenon has an official medical name: "ice cream headache." It's also commonly known as "brain freeze."

When something cold touches the roof of your mouth (the palate), the blood vessels there are rapidly chilled. Your brain then decides, "This is an emergency - the head is getting too cold!" and rushes to dilate blood vessels to send warm blood flowing in. This sudden dilation of blood vessels stimulates the surrounding nerves, triggering the pain.

Why Your Temples Hurt

The cold is in your mouth, yet the pain is felt in your temples and forehead. This is a phenomenon called "referred pain." The trigeminal nerve, which carries sensations from the roof of your mouth, also handles sensations from your forehead and temples. Your brain can't pinpoint the exact source of the pain and mistakenly concludes, "It's probably somewhere around the forehead."

Stopping It Is Surprisingly Easy

If you get an ice cream headache, press your tongue against the roof of your mouth. The warmth of your tongue heats up the blood vessels in the palate, and the pain subsides within seconds. Alternatively, taking a small sip of a warm drink also works well.

Of course, if you eat cold things slowly in the first place, it won't happen at all. Instead of letting it hit the roof of your mouth directly, warm it up a bit on your tongue before swallowing. That alone will keep you free from that sharp sting. Then again, telling someone to "eat slowly" on a hot day with shaved ice in front of them is admittedly a tall order. (Books about the wonders of the human body are full of fascinating discoveries like this)