Casualty Evacuation by Female Litter Teams Under Hot-Dry Conditions

摘要

A Defense Women's Health Research Program sponsored protocol was conducted at Yuma Proving Ground (YPG), AZ, on 19-27 September 1995. Four female subjects participated in four activities in a hot, dry environment: walk-rest exercise in MOPP-0 and MOPP-4 at 3 mph for a maximum of 2 h 40 min and self- paced, two-person litter carriage with a 68 kg (150 lbs) 'casualty' in the same uniforms. Metabolic rates for the walking and self-paced litter carriage tasks were also measured. The results are summarized in Table 1. For walking in MOPP- 0, mean endurance time (ET) was 140 plus or minus 40 min and the increase in rectal temperature (Tre) was 0.93 plus or minus 0.27 C vs. an ET of 29 plus or minus 8 min and a Tre of 1.28 plus or minus 0.40 C in MOPP-4. For the litter carriage the ET values in MOPP-0 and MOPP-4 were 59 plus or minus 35 min vs. 43 plus or minus 19 min and for Tre the values were 0.69 plus or minus 0.51 C vs. 0.76 plus or minus 0.41. For walking, the increased physiological strain related to the chemical protective (CP) clothing worn in MOPP-4 was the apparent reason for the reduced activity time on the second day. During both days of litter carriage, the most common reason for termination was skeletal-muscular problems rather than heat stress, but the last subject in MOPP-4 stopped with indicators of thermal strain. This suggests that although muscular-skeletal problems were the proximate limiting factor for most subjects, thermal strain would have occurred within a short time. Mean results for Tre were compared with values predicted by two models: the Heat Strain Decision Aid (HSDA) and the SCENARIO model. Comparisons of predictive modeling results to subject responses show reasonable agreement with mean subject responses for both models.