RESUMEN
BACKGROUND: The purpose of this study was to compare thermoregulatory and subjective responses of 12 test subjects (10 male, 2 female) wearing 5 different Joint Service Lightweight Integrated Suit Technology (JSLIST) prototype and 3 different currently fielded control chemical/ biological (CB) protective overgarments. METHODS: The overgarments were compared while subjects attempted to complete 100 min of moderate exercise (400 W) in an environmental chamber (35 degrees C/50% rh). Rectal temperature (Tre), skin temperature, heart rate, sweating rate, and test time, as well as subjective symptoms of heat illness were measured. Data were analyzed for times earlier than 100 min because subjects were not usually able to complete the 100-min trials. RESULTS: At 50 min, of the 3 controls, the Army/Air Force Battledress Overgarment (BDO) imposed significantly greater heat strain (indicated by Tre 37.90 degrees C) than the Marine Saratoga (SAR) (Tre 37.68 degrees C) and Navy Chemical Protective Overgarment (CPO) (Tre 37.69 degrees C). The JSLIST prototype garments imposed heat strain (50 min Tre 37.73-37.86 degrees C) as well as subjective perception of heat strain, that ranged between the warmest and coolest controls. CONCLUSIONS: In the environmental and exercise test conditions of this study, we did not find the five JSLIST overgarments to be consistently different from one another. Subjects in the control garments were and felt generally warmer (BDO) or cooler (SAR, CPO) than in the JSLIST prototype garments.