Researchers at Harvard think they have cracked the code of the elusive brain freeze - or sphenopalatine ganglioneuraliga - and think it may help soldiers with combat trauma.

The chilly headache may be caused by an increase in blood flow to the brain when the upper palate is stimulated with something very cold, like ice water or ice cream.  Scientists hypothesize that the surge in blood flow could be part of an involuntary temperature-regulation response meant to keep the brain functioning in a warm environment.  

Scientists hope the insight will help them understand and better treat migraines and headaches brought on by post-traumatic stress.