Nunneley S A, Maldonado R J
Aviat Space Environ Med. 1983 Jun;54(6):496-9.
Liquid-conditioned garments (LCG's) may be useful in alleviating heat stress on aircrew members. This study evaluated the effects of a liquid-cooled vest and/or cap on subjects exposed to a thermal environment which simulated the stress of low-level flight in hot weather. The chamber was set at dry bulb temperature 35 degrees C, wet bulb temperature 26 degrees C, and black globe temperature 43 degrees C. Subjects were eight men, aged 23-45 yr. Each subject was studied in four 100-min exposures: uncooled control (XX); head cooling only (HX); torso cooling only (XT); and combined head and torso cooling (HT). Cooling effects were evaluated by using rectal temperature (Tre); heart rate (HR); sweat rate (SRF and SRT for forehead and total body, respectively); and subjective comfort. Uncooled runs (XX) produced final values: Tre = 37.8 degrees C, HR = 94 beats/min, SRT = 25 g/m2 X h and SRF = 45 g/m2 X h. Combined head and torso cooling maintained the subjects at nearly their initial (baseline) state. Cap effects per se were assessed by comparing HX to XX, and HT to XT. Head cooling proved 2-3 times as efficient as torso cooling, although limited by the small surface area involved. We conclude that the specific effects of head cooling in improving comfort and diminishing forehead sweating, as well as the efficient systemic cooling observed, justify further work on cockpit applications.
液冷服装（LCG）可能有助于减轻空勤人员的热应激。本研究评估了液冷背心和/或帽子对暴露于模拟炎热天气下低空飞行应激热环境中的受试者的影响。试验箱设定的干球温度为35摄氏度，湿球温度为26摄氏度，黑球温度为43摄氏度。受试者为8名年龄在23至45岁之间的男性。每位受试者接受了四次100分钟的暴露试验：无冷却对照组（XX）；仅头部冷却（HX）；仅躯干冷却（XT）；以及头部和躯干联合冷却（HT）。通过直肠温度（Tre）、心率（HR）、出汗率（前额和全身出汗率分别为SRF和SRT）以及主观舒适度来评估冷却效果。无冷却试验（XX）产生的最终值为：Tre = 37.8摄氏度，HR = 94次/分钟，SRT = 25克/平方米·小时，SRF = 45克/平方米·小时。头部和躯干联合冷却使受试者维持在接近初始（基线）状态。通过比较HX与XX以及HT与XT来评估帽子本身的效果。尽管涉及的表面积较小，但头部冷却的效率被证明是躯干冷却的2至3倍。我们得出结论，头部冷却在提高舒适度和减少前额出汗方面的特定效果，以及观察到的有效的全身冷却效果，为在驾驶舱应用方面开展进一步工作提供了依据。
