Effect of Protective Clothing Ensembles on Artillery Battery Crew Performance

Abstract : Performance of three 9-man crews was evaluated while firing 90 rounds in a safe and expedient manner, with swabbing of the breech after each round. Each 9-man crew fired on three non-consecutive days; the independent variable among days was the MOPP level worn (BDU vs MOPP IV vs MOPP IV with cooling). All 90 rounds were fired by all three crews when wearing BDU. Despite similar climatic conditions, 2 of the 3 MOPP IV iterations were prematurely terminated due to high rectal temperatures and/or presyncopal symptoms. During the MOPP IV trial average time to fire one round increased from the first to the second 45 rounds. In contrast crews wearing BDU did not increase firing time. When cooling was added to the MOPP IV configuration (cool MOPP), all iterations were completed and performance was enhanced despite warmer environmental conditions. As in the BDU trials, the time to fire a single round was unchanged over time, and was significantly less than that for MOPP IV. Significantly higher sweat losses in MOPP IV were reflected in the crew's enhanced perception of sweatiness, thirst, hyperthermia, and headache. Full encapsulation of crew members in chemical protective gear imposed a heat stress which reduced work tolerance and performance, but these decrements were lessened by microclimate cooling to the thorax and face.