Glycerine and creatine improve heat tolerance

Athletic performance decreases in the heat. Physical activity increases heat production in the body and high ambient temperatures further exacerbate this condition. Adequate hydration (water retention in the body) is a critical factor in controlling body temperature. Creatine and glycerol increase the body's capacity to store water. Researchers from Scotland have found that supplementation with creatine and glycerol (alone or in combination) reduces heart rate, body temperature and perceived exertion during endurance exercise in the heat (90 degrees Fahrenheit (which is about 32 degrees Celsius), 70 percent humidity). While the combination of creatine and glycerol increased water retention in the body the most, creatine alone was just as effective in reducing cardiovascular stress and thermal stress during exercise.
In the past, many sports physicians have warned athletes not to take creatine when exercising in high heat. This study shows that the exact opposite is true: creatine improves heat tolerance.
(International Journal Sports Nutrition Exercise Metabolism, 17: 70-91, 2007)