Claire Johnson and Professor Ron Eccles, from Cardiff University's Common Cold Center, recruited 180 volunteers, half of whom they got to immerse their feet in ice and cold water for 20 minutes.

The other 90 in tests during the common cold "season" sat with their feet in an empty bowl.

During the next four or five days, almost a third (29 percent) of the chilled volunteers developed cold symptoms -- compared to just 9 percent in the control group, the scientists said.

Cardiff's Common Cold Center says it is the world's only center dedicated to researching and testing new medicines for the treatment of flu and the common cold.