Heat strain during at-sea helicopter operations and the effect of passive microclimate cooling.
Twelve Navy H-3 helicopter aircrew members were monitored (heart rate, skin and rectal temperatures) in both microclimate cooling (ice) vest and non-vest conditions during at-sea operations in the high heat environment of the Persian Gulf. During all flights and flight phases, ambient dry bulb temperatures ranged from 31.0 degrees C (in-flight) to 48.6 degrees C (hover). Heart rate was greatest during hover and on-deck (range: 89.9 to 145.0 beats/min) without an ice vest, yet was significantly reduced with ice (range: 79.7 to 86.0 beats/min) (p less than 0.05). Rectal temperature was not found to be different between vest and non-vest conditions; however, change across flight phases in both conditions was significant (p less than 0.05). Analysis of variance demonstrated significantly lower mean weighted skin temperatures (p less than 0.05) when wearing the ice vest. These data suggest that wearing a protective cooling vest can reduce the heat strain associated with helicopter flight in high heat environments.
Banta
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Physiological Performance and Operational Medicine Department, Naval Health Research Center, San Diego, CA 92186-5122.
Braun
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D000328:Adult; D000337:Aerospace Medicine; D001831:Body Temperature; D003020:Clothing; D003080:Cold Temperature; D006339:Heart Rate; D006359:Heat Exhaustion / Q000503:physiopathology* / Q000517:prevention & control*; D006801:Humans; D008889:Military Personnel; D012881:Skin Temperature