According to Johns Hopkins University, a bout of radiating
pain in your head after eating cold food is known as cold
neuralgia or sphenopalatine ganglioneuralgia. It is likely
caused by your body entering survival mode when it detects a
freezing temperature on the roof of the mouth: our system
constricts blood vessels in the palate to preserve our core
temperature. When they rapidly open back up, a pain signal is
sent to the brain via the trigeminal nerve. Since that nerve
leads directly to the midface and forehead, your face bears the
brunt of the referred pain from the mouth.
A brain freeze
typically lasts less than five minutes, but when your head is
throbbing, that can feel like forever. To minimize the pain, the
best strategy is to warm the palate up. You can do this by
pressing your tongue or a thumb against the roof of your mouth,
by drinking a warm liquid, or both. Covering your face and
breathing into your hands can also warm the air inside your
mouth that was chilled by the ice cream.