Heat strain evaluation of chemical protective garments

Background: The purpose of this study was to compare thermoregulatory and s ubjective responses of 12 test subjects (10 male, 2 female) wearing 5 diffe rent Joint Service Lightweight integrated Suit Technology (JSLIST) prototyp e and 3 different currently fielded control chemical/biological (CB) protec tive overgarments. Methods: The overgarments were compared while subjects a ttempted to complete 100 min of moderate exercise (400 W) in an environment al chamber (35 degreesC/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 10 0 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 Ove rgarment (BDO) imposed significantly greater heat strain (indicated by Tre 37.90 degreesC) than the Marine Saratoga (SAR) (TIE 37.68 degreesC) and Nav y Chemical Protective Overgarment (CPO) (Tre 37.69 degreesC). The JSLIST pr ototype garments imposed heat strain (50 min Tre 37.73-37.86 degreesC) as w ell as subjective perception of heat strain, that ranged between the warmes t and coolest controls. Conclusions: In the environmental and exercise test conditions of this study, we did not find the live JSLIST overgarments to be consistently different from one another. Subjects in the control garment s were and felt generally warmer (BDO) or cooler (SAR, CPO) than in the JSL IST prototype garments.a93