Accession Number : ADA292315

Title :   Evaluation of the Efficiency of Microclimate Cooling in a Hot Weather CBR Environment.

Descriptive Note : Final rept.,

Corporate Author : GEO-CENTERS INC FORT WASHINGTON MD

Personal Author(s) : Wittmers, L. ; Hoffman, R. ; Israel, D. ; Ingersoll, B. ; Canine, K.

PDF Url : ADA292315

Report Date : 22 NOV 1994

Pagination or Media Count : 95

Abstract : The threat of chemical warfare associated with the war in the Persian Gulf revealed that insufficient information available regarding military personnel who can be exposed to both a hot environment and chemical/biological attack. The chemical, biological, radiological (CBR) protective ensembles worn under threat of chemical/biological attack prevent noxious agents from reaching the skin; however heat metabolically generated or gained from the environment is prevented from dissipating. Thus in this scenario, microclimate cooling may be essential to prevent heat injury. This study was designed to determine the efficiency of a microclimate cooling system (MC'S) in preventing heat strain in six unacclimated males who performed moderate exercise (walking at 3 mph, 2% (grade) in a hot environment (100f), while encapsulated in a chemical protective overgarment with either no cooling (NC), intermediate cooling (IC) (coolant flow rate = 225 ml/min), or maximal cooling (MC) (coolant flow rate = 450 ml/min). Heart rate (HR), core temperature (Tr%) and stay time were measured as indices of heat strain. There was 110 difference in HR or Tr% at 50 min and 90 min between the IC and MC conditions, and all participants reached the maximal time limit (120 min) in both conditions. HR and T, were lower in the IC and MC conditions than the NC condition at min 90 and stay time was longer in IC and MC than NC. The USC of this MCS reduced cardiovascular stress, as estimated by increases in 1-HR and reduced thermal stress, as estimated by increases in Tr; however, the higher coolant flow rate conferred no thermoregulatory advantage over the lower flow rate.

Descriptors :   *BIOLOGICAL WARFARE, *CHEMICAL WARFARE, *PROTECTIVE CLOTHING, *MICROCLIMATOLOGY, STRESSES, MILITARY PERSONNEL, WARFARE, CORES, THREATS, TEMPERATURE, PERSIAN GULF, EFFICIENCY, COOLING, ESTIMATES, FLOW RATE, TOXIC AGENTS, COOLING AND VENTILATING EQUIPMENT, WOUNDS AND INJURIES, COOLANTS, HEART RATE, CARDIOVASCULAR SYSTEM, HEAT STRESS(PHYSIOLOGY).

Subject Categories : Stress Physiology
      Chemical, Biological and Radiological Warfare
      Human Factors Engineering & Man Machine System

Distribution Statement : APPROVED FOR PUBLIC RELEASE