Cooling jackets are often used by athletes to chill their core body temperature before, during or after exercise. The jackets' cooling properties take the edge off extreme heat, possibly avoiding hyperthermia. While in theory they sound like a good idea, do they work?
A group of researchers from the University of Western Australia and the Western Australian Institute of Sport decided to find out, testing 12 active young men in three different conditions. The men exercised for a half-hour at 75% of their maximum ability in a controlled environment where the temperature was about 95 degrees with 52% relative humidity. Afterward they spend 30 minutes in cooler temperatures.
During that cooling period the participants were randomly assigned to wear a gel-based cooling jacket, a jacket made with phase change material, which absorbs the body's excess heat, or no jacket at all (this served as a control).
Skin temperatures and core temperatures at the beginning of the exercise period and during it didn't vary much among the participants. More important, there was very little variation in skin or core temperature cooling among the three conditions.
The researchers noted that while there were virtually no differences between the jackets in terms of cooling, the jacket with the phase change material may warrant more study, since it can stay colder at higher temperatures than some other materials and can sustain a steady temperature during use.
The study appears in the April issue of the Journal of Athletic Training.
-- Jeannine Stein
Photo credit: Reed Saxon / Associated Press