Why do we get "brain freeze"?

"Brain freeze" is that sharp, short-lasting headache one gets when eating or drinking something cold - typically ice cream or a milkshake - on a hot day. Also known as "ice cream headache" or "frozen brain syndrome," brain freeze affects about one third of the population and does not occur during cool weather. The pain occurs when the brain's blood vessels dilate. The dilation is likely the result of a nerve centre, located above the roof of your mouth, reacting to the cold stimulus. The nerve centre overreacts, causing the pain. You can enjoy a tasty ice cream treat, but you should try to keep away from the roof of your mouth.