There is nothing better on a hot summer day than an ice-cold beverage or a big scoop of your favorite ice cream. We’ve all gotten a bit too overeager and as that cold drink or treat hits the back of our mouth, a peculiar and painful thing happens. As though someone has begun stabbing you with tiny needles in the center of your forehead or temples, the dreaded ice-cream headache sets in.
You clutch at your temples, and probably emit some sort of groan of pain, and yet the delicious flavor of that Slurpee is still flooding your mouth. Commonly called a brain freeze, this bizarre phenomenon is a mixture of pain derived directly from pleasure. The real question is, what is a brain freeze? And what sort of damage, if any, do these icy episodes do to our brains?
Recommended Video for you:
The Science Behind an Ice-Cream Headache
Despite the fact that this chilly event happens to everyone at least once in your life (unless you have literally never consumed ice water, ice cream, or a milkshake), very little time and money has been contributed to study this universal phenomenon. Scientists think they understand the basic principle behind this strange sensation, but no one is actually 100% sure. 
Some of the leading guesses relate to the capillaries in our sinuses. As these tiny blood vessels are rapidly cooled when the air we inhale drops in temperature whilst eating something cold, they dilate and scrunch up, before re-expanding after they warm back up. This tightening in the nasal cavity may create the sensation in your forehead, because this change dilation causes a pressure change, which is registered in the tissues of the palate by pain receptors. This nerve impulse of pain may then pass through the trigeminal nerve, an important hub for nerves in the face that directly links to a point in the forehead when pain is detected. That’s why we feel our brain “freeze” from a point near the forehead or temples. It is a form of “referred” pain that has more to do with neural activity and nerve endings than actual location of the affected area. 
Another theory suggests that the capillaries and blood vessel constriction that occurs during a brain freeze actually forces an increase in blood flow through the anterior cerebral artery. When excess blood is suddenly flooding through the artery, the pressure increase is registered as pain in the forehead. When the pressure returns to normal levels in a few seconds or minutes, the pain disappears. Again, no one is completely sure how or why these brain freezes, but these findings seem to make the most sense, given the normal functions of nerves and blood vessels in the face. That still doesn’t answer a more important question though…
Are We Damaging Our Brains When We “Freeze” Them?
It seems like we do everything possible to protect our brains from harm (including bicycle helmets and our own skull!), so some people assume that putting your brain on ice, even for a minute, is a dangerous idea. Flexing your blood vessels rapidly and inducing phantom pains in your forehead doesn’t seem natural, right? 
The truth of the matter is that the brain is a bit tougher than we give it credit for. In fact, our brain’s temperature changes whenever we get a fever, or when we spend an excessive amount of time in the hot sun or the bitter cold. Our body, however, is very good at maintaining homeostasis and compensates to keep our brain within a safe temperature range. It even has symptoms to inform us when the brain is “heating up” or “cooling off”, including fevers, sweating, pain, cognitive impairment, and a host of other telling signs that something is wrong. The thing is, the brain can survive at rather impressively low temperatures, such as the temperatures induced during invasive neurological surgeries. For some procedures, the brain must be cooled to temperatures as low as 64 degrees Fahrenheit (18 degrees Celsius). That is roughly 35 degrees lower than the ideal range of 98.6-100.4.
Even after those successful brain surgeries, where the brain region maintains about 15% of its typical energy and metabolic function, the temperature is returned to normal and the brain tissue is completely undamaged. In other words, if the brain can handle hours of frigidity, a few seconds of temporary pain isn’t going to do any lasting damage, just remember to pace yourself and gulp that water slowly. Problem solved! Let’s be honest, nobody wants to end up like that guy, no matter how delicious that ice cream is! 
