Why do we get brain freeze from eating cold food too fast?

Brain freeze, scientifically known as sphenopalatine ganglioneuralgia, happens when something very cold touches the roof of your mouth—the palate.

When this happens quickly, the rapid cooling and then warming of the tissues causes the capillaries in your palate to constrict and then rapidly dilate. This sudden change is detected by the trigeminal nerve, which is responsible for sensation in your face and mouth.

Because the nerves in the palate are closely linked to those in the forehead, your brain misinterprets the pain signal coming from your mouth as coming from your head. Essentially, your brain gets confused by the nerve input and tries to alleviate the "threat" of the cold by dilating blood vessels in your head to warm the area up, which triggers that sharp, stabbing headache.

It’s essentially a protective reflex gone wrong! Eating cold things more slowly helps give your palate time to adjust, preventing the nerves from sending that distress signal.