Kuhlemeier K V, Wood T B
Am Ind Hyg Assoc J. 1979 Dec;40(12):1097-1103. doi: 10.1080/15298667991430758.
Forty-six industrial workers completed a total of 653 one-hour work bouts requiring an average of 122-235 kcal/M2/hr in an environmental chamber maintained at heat stress levels ranging from 8-37 degrees C wet bulb globe temperature (WBGT). Heart rates (HR) and rectal temperatures (Tre) were measured at the end of each work bout. Environmental heat stress levels were divided into two groups - those above and those below the permissible exposure limits (PEL). The PEL is the proposed maximum environmental thermal stress to which industrial workers can be exposed without endangering their health. The number of observations in each of these regions was further divided into those which were above the recommended limits of a World Health Organization study group (HR less than or equal to 110 bpm, Tre less than or equal to 38.0 degrees C) and those which were not. The number of "safe" (HR less than or equal to 110 bpm, Tre less than or equal to 38.0 degrees C) observations in environments with heat stress less than or equal to the PEL ranged from 100% to 2.4% depending on subject acclimatization and work rate. The degree of protection was always less in the winter than in the summer and was less for higher work rates. Men who normally worked in hot environments had fewer "excessive" HR's and Tre's than those who did not.
46名产业工人在环境舱内完成了总共653次为时1小时的工作时段，环境舱内的热应激水平保持在湿球黑球温度（WBGT）8 - 37摄氏度范围内，工作时平均每平方米每小时消耗122 - 235千卡热量。每次工作时段结束时测量心率（HR）和直肠温度（Tre）。环境热应激水平分为两组——高于和低于允许暴露限值（PEL）的。PEL是指产业工人在不危害健康的情况下可暴露于其中的建议最大环境热应激水平。这两个区域中每个区域的观察次数又进一步分为高于世界卫生组织研究小组推荐限值（HR小于或等于110次/分钟，Tre小于或等于38.0摄氏度）和未高于该限值的。在热应激水平小于或等于PEL的环境中，“安全”（HR小于或等于110次/分钟，Tre小于或等于38.0摄氏度）观察次数的比例从100%到2.4%不等，这取决于受试者的适应情况和工作强度。冬季的保护程度总是低于夏季，且工作强度越高保护程度越低。通常在炎热环境中工作的男性出现“过高”HR和Tre的情况比不常在炎热环境中工作的男性少。
