"First, let’s get one thing straight. “This condition is referred to as an ‘ice-cream headache,’ ” says Stacey Gray, a sinus surgeon at the Massachusetts Eye and Ear Infirmary in Boston. “It’s a very technical term.” Although there’s no published paper saying as much, a milkshake slurped too quickly probably does not actually lower brain temperature. Besides, Gray says, the temporary pain can’t do any harm because it has nothing to do with the brain.
There are two schools of thought on what causes the ice-cream headache. The drink may chill the air in your sinuses and cause the blood vessels in the nasal cavity near your forehead to constrict, creating pain similar to a migraine. Or perhaps it touches off a branch of the trigeminal nerve in your mouth, triggering a pain response in the nerve that’s responsible for facial sensation."
Later he quotes a doctor explaining why lowering brain temperature temporarily is not a big deal:
"“Even if the patient wasn’t anesthetized, at that temperature they would be in a noninteractive state, unable to sense stimuli or produce a response,” Tamargo says. “But once you warm the brain up, it picks right up from where it left off. It’s not harmful at all.” So whether your brain is frozen or not, if you can handle a little pain, slurp away."
Have you ever heard of this before? Long-term brain damage? Seriously?