Why whenever I eat ice cream too quickly, do I get a slight headache?

That mild achin’ in your head you speak of is known, in not-so-scientific terms, as an “ice cream headache” or “brain freeze.” And while some like it cold–especially those of us who are just CRAZY about ice cream–this headache is one reason why you shouldn’t attack that pint of Ben ‘n’ Jerry’s too quickly. When you eat something cold that fast, the blood vessels in your mouth, neck and head work to help keep you warm by contracting, or shrinking, a little so that less blood gets sent to these body parts. That way, large amounts of heat won’t leave your body. (If the flow of blood was not held back in this manner then more heat would escape through the blood in your head and neck’s vessels and out from your skin’s surface.) Just think of it as your body’s special defense against the cold, like what happens to you outdoors on a winter day. That’s when freezing temperatures make the blood vessels in your skin contract, making you look pale.