While scientists have never been able to fully explain the “brain freeze” phenomenon, the instantaneous and often-debilitating pain in the temples and forehead that comes after eating something frozen, a group of researchers have recently suggested that the “ice cream headache” may be caused by a sudden local change in blood flow to the brain.

Researchers from the study, presented at his year's Experimental Biology meeting in San Diego, monitored the blood flow of 13 participants drinking ice water with the straw pressing on the upper palate and while they drank room temperature water.

Participants were asked to raise their hands when they started to feel the “brain freeze” and then again when the headache went away.

Results from the diagnostic imaging tests of participant’s blood flow showed that a rush of blood from the anterior cerebral artery flooded the brain with blood the same time participants felt the momentary headache that receded once the same vessel started to constrict and limit blood flow.

Lead researcher Jorge Serrador of Harvard Medical School said that the sudden rush of blood could be a self-defense mechanism that keeps the brain warm and working.

Researchers explain the sudden flood of blood may be painful because it raises pressure in the skull, but the pain recedes when the artery constricts to bring the pressure back down to keep it from reaching dangerous levels.

"The brain is one of the relatively important organs in the body, and it needs to be working all the time," Serrador said in a statement. "It's fairly sensitive to temperature, so vasodilation might be moving warm blood inside tissue to make sure the brain stays warm."

Since people who have migraines are more likely to experience brain freeze compared to others, researchers said that the mysterious brain freeze may share common mechanism with other types of head pain and could offer potential targets for treating pain from migraines to posttraumatic headaches.

The findings were presented at the Experimental Biology 2012 conference, and should be considered preliminary until they are published in a peer-reviewed medical journal.