Filed under: Extreme environments
Heat-related injuries are a threat to Warfighters, even those in top physical condition, deployed to extreme environments. Heat acclimatization is necessary to ensure that the health and performance of Warfighters is not compromised to a dangerous degree when exposed to heat stress.
Take it slow. For unacclimatized Warfighters, physical exertion should be limited in intensity and time. Allow 9-14 days of progressive heat exposure and exertion—more for less-fit Warfighters, less for more-fit Warfighters.
Don’t overdo it; don’t underdo it! Heat acclimatization requires exposure at least two hours per day (can be two one-hour segments) while engaged in a cardiovascular exercise (which should increase in intensity each day of the acclimatization period).
It’s all relative. The level of heat acclimatization achieved is relative to the exertion normally expended by the Warfighter. If light exertion is the norm, the level of heat acclimatization after two weeks will match that. If more strenuous exertion is called for, additional acclimatization and possibly improved fitness is required.
Work smart. If Warfighters must perform physical work during the acclimatization period, take advantage of the cooler hours during the morning, evening, and night.
Stay hydrated. Adequate water is essential. Heat acclimatization increases sweating and, therefore, water requirements. Dehydration rapidly degrades safety and performance, even for those who are already heat acclimatized or in top physical condition.
For a more detailed look at heat stress and acclimatization, read HPRC’s reports on managing heat exposure.
Research at USARIEM (U.S. Army Research Institute of Environmental Medicine) was featured in a article by writer Christopher Solomon titled "G.I. Joe and the House of Pain" in a special issue of Outside Magazine about human performance. The author spent time in the research lab's heat chamber, altitude chamber, and cold-water pool—conditions that simulate the extreme environmental conditions found in theater. He interviewed research physiologists there about USARIEM's work over the past 50 years as well as its current studies, all of which address the crucial issues of Warfighter health and performance in extreme environments.
Runnersworld.com has an article that cites a new study from the Journal of Applied Physiology which reports that 10 days of extreme heat acclimation can improve performance by six to eight percent.
Click on link below to access article.