Relating heat strain in the chemical defense ensemble to the ambient environment.

Management of military personnel in chemical protective clothing (CPC) is difficult. The purpose of this study was to test a 10 degrees C wet bulb globe temperature (WBGT) adjustment for CPC. Five male subjects walked for 1 hour at 400 kcal/hour twice in a U.S. military CPC at a WBGT = 20 degrees C, and once without protective clothing (NoPC) in a WBGT = 30 degrees C followed by a 45 minute seated recovery. No significant differences (p > 0.1) were observed between CPC trials, nor between the mean of the CPC trials and NoPC for heart rate, sweat rate, or change in rectal or mean skin temperatures during the work or recovery phases. Correlations between mean CPC and NoPC were all greater than 0.68. These results suggest minimal differences in responses between CPC and NoPC when the WBGT difference equaled 10 degrees C.