THERMAL PERFORMANCE OF PERMEABLE VERSUSnIMPERMEABLE HOODS WORN BY MEN IN CB ENSEMBLE WORKING IN A TROPICAL ENVIRONMENT

摘要

A hood fabricated from twill cloth, MIL-C-81280B, with air permeability of 175 cu ft/sq ft/min of 0.5 inch of water was evaluated by comparison with the standard M6A2 impermeable hood and no hooded condition. Men walked for 6.5 miles at an average rate of 2.5 mph in a hot environment with average wet-bulb globe temperature between 81 and 87F. Twelve replications were performed. The permeable hood was found to be statistically different from either impermeable hood or no hood. Very little operational advantage can be gained, however, by depending solely on the impermeable hood to remove excess heat.