1 May 2013 Last updated at 19:11 ET By Eleanor Bradford BBC Scotland Health Correspondent
Volunteers in Edinburgh are having their brains cooled as part of a trial of a new treatment for stroke.
Healthy people are testing a cooling cap as part of a European project to see if cooling the body shortly after a stroke reduces damage to the brain.
About 1,000 Europeans die from a stroke every day, with twice as many being left disabled.
The Eurohype study will find out whether therapeutic hypothermia could be used to improve survival.
The technique is already used to improve survival in a variety of people at risk of brain injury, including newborn babies and cardiac patients.
It's like sitting in the park in winter without a hat
Prof Malcolm Macleod, head of experimental neuroscience at the University of Edinburgh's Centre for Clinical Brain Sciences, said: "We think that it may be that within all of our cells there are really quite primitive protective mechanisms that protect us from rapid changes in temperature.
"We think that what we might be able to do is reawaken those processes in the brains of patients who have had strokes to protect their brain cells until such time as the body's own repair mechanisms can kick in and have their effect."
Stroke patients in other parts of Europe are already being cooled as part of the 9.5m four-year study.
Read more:
Cap 'cools' brain for stroke trial