The ache subsided again once blood flow was restricted.
The findings were presented at the meeting Experimental Biology 2012 being in San Diego.
By bringing on brain freeze in the laboratory the researchers were able to study a headache from beginning to end without the need for drugs that would mask the causes and symptoms of the pain.
The volunteers drank iced water through a straw that was pressed against their palate and then drank water at room temperature.
Blood flow was monitored using a hand held Doppler.
It was found that the anterior cerebral artery dilated rapidly and flooded the brain with blood in conjunction to when the volunteers felt pain. Soon after this dilation occurred, the same vessel constricted as the volunteers' pain receded.
Co-author Jorge Serrador of Harvard Medical School and the War Related Illness and Injury Study Centre of the Veterans Affairs New Jersey Health Care System, said: "The brain is one of the relatively important organs in the body, and it needs to be working all the time. "It's fairly sensitive to temperature, so vasodilatation might be moving warm blood inside tissue to make sure the brain stays warm."
But because the skull is a closed structure, the sudden influx of blood could raise pressure and induce pain, he said.
By constricting the blood vessel again the body could be acting to reduce the pressure before it reaches dangerous levels, he said.
Similar alterations in blood flow could be at work in migraines, post traumatic headaches, and other headache types, he added.
If further research confirms these suspicions, then finding ways to control blood flow could offer new treatments for these conditions. Drugs that block sudden vasodilatation or target channels involved specifically in the vasodilatation of headaches could be one way of changing headaches' course
