Mairiaux P H, Libert J P, Candas V, Vogt J J
Aviat Space Environ Med. 1984 Oct;55(10):935-40.
The effect of the time presentation of a given external heat load was examined on five subjects exercising at a constant work load (50 W). The subjects, dressed in briefs, were exposed to cyclic variations for 120 min in air temperatures between 51 degrees C and 23 degrees C, under three different schedules involving heat pulses of 10-min, 20-min and 30-min duration, respectively. The strain induced by each of these conditions was compared in terms of both physiological and perceptual criteria. Results showed that between conditions, there were significant differences in skin temperature levels but not in core temperature levels, body heat storage, or body weight loss. Perception of effort and thermal sensation ratings both exhibited similar changes in all three conditions. Due to the time constant of the sweating response, sweating rates and skin wettednesses at the end of the heat pulses were lower for 10-min heat pulses than for those of 20- and 30-min duration, and these differences were perceived by the subjects. Lower perceived skin wettedness ratings are thus suggested as the main factor to explain why all subjects rated the 10-min heating-cooling cycle as the least strenuous and uncomfortable condition. It is concluded that under the conditions of this study, perceptual criteria associated with physiological criteria represent a useful means of discriminating slight differences in strain.
研究了在给定外部热负荷的不同呈现时间下，五名受试者在恒定工作负荷（50瓦）下运动时的情况。受试者仅穿着内裤，在三种不同的时间表下，于51摄氏度至23摄氏度的气温中经历120分钟的循环变化，这三种时间表分别涉及持续时间为10分钟、20分钟和30分钟的热脉冲。从生理和感知标准两方面比较了每种条件下所诱发的应激反应。结果显示，不同条件之间，皮肤温度水平存在显著差异，但核心温度水平、身体蓄热或体重减轻方面并无差异。在所有三种条件下，努力感知和热感觉评级均呈现出相似的变化。由于出汗反应的时间常数，10分钟热脉冲结束时的出汗率和皮肤湿润度低于20分钟和30分钟持续时间的热脉冲，受试者也察觉到了这些差异。因此，较低的皮肤湿润度感知评级被认为是解释为何所有受试者将10分钟加热 - 冷却循环评为最轻松和最不难受条件的主要因素。得出的结论是，在本研究条件下，与生理标准相关的感知标准是区分应激反应细微差异的有用手段。
