Body Armor in a Hot Humid Environment. Part Ii. Studies in Heat Acclimatized Men

摘要

The standard issue Marine Corps personnel body armor vest (M1955) was tested for its effect on men working under hot humid conditions approximating those seen in Southeast Asia. This vest is largely impervious to the passage of water vapor and thereby impedes evaporative cooling over the chest. Body armor produces a pronounced effect reflected by an increase in rectal temperature in the subjects when they are wearing the armor. This effect is restricted to a range of environment bracketed by 82 to 88F WBGT (approximately). Below this level, heat loss from areas other than the chest is sufficient to dissipate body heat effectively. Above this range, the stress of the environment is so great and the evaporation of sweat is so inefficient that wearing body armor makes little difference. The effect of wearing armor in this range (82-88F) is equivalent to a 5F increase in the WBGT for unarmored men. The experiment was designed to eliminate the weight of the armor as a source of difference. (Author)