1 year ago
Last edited at 9:25AM on 8/8/2012
Just above the soft pallet of your mouth is a collection of intertwined nerves and blood vessels. When you drink something very cold the cold liquid causes the blood vessels contract. The blood vessels rebound very quickly and dilate, sometimes too much, pushing on the nerves causing pain, or what we experience as brain freeze. The effects are very temporary as the blood vessels return to normal within seconds.
It's when the uvula, at the back of your mouth, becomes cold. This is very closely connected to the brain, and it gives you a sharp headache. When this happens, you can press your tongue against the roof of your mouth, that will stop the pain most quickly.