HEAT STRAIN IN THE CANADIAN FORCES CHEMICAL DEFENSE CLOTHING - PROBLEMS AND SOLUTIONS

The Canadian Forces chemical defence protective clothing can induce an overwhelming strain on one's ability to regulate body temperature. Re cently a number of investigations have been completed at the Defence a nd Civil Institute of Environmental Medicine that focused initially on understanding the interaction of metabolic rate, ambient temperature, and ambient vapour pressure on the severity of heat strain associated with wearing the protective clothing. This paper presents a summary o f these initial studies together with an overview of different attempt s to reduce heat strain during exercise in a hot environment. Factors such as improved aerobic fitness or a period of dry heat acclimation h ave little if any benefit on tolerance time while wearing the clothing during light or moderate exercise. The best solution to the problem o f heat strain remains the use of microclimate conditioning (personal c ooling), and these techniques have been successful for Naval and Air F orce personnel. For our Land Forces, however, microclimate conditionin g is not feasible until a lightweight high-energy power source is deve loped.