Eating ice cream or really chilled soft drinks can trigger crushing headaches in some people, momentarily freezing the brain. New insight into how this happens could open the way for new treatment of other types of headaches, including migraine. Researchers from the Harvard Medical School tracked blood flow to the brain while people drank iced water or lukewarm water. Both were drunk through a straw that was pressed against the roof of the mouth, and the volunteers signalled when the pain started and when it ended. The results showed that the pain coincided with an artery, the anterior cerebral artery, opening up and flooding the brain with blood. It then constricted and pain receded, the Daily Mail reported.