Some responses of humans to thermal radiation

Abstract

The effects of thermal radiation on heart rate, ventilation rate, and oxygen consumption rate were investigated at various conditions of dry-bulb temperature, air velocity, and exercise. Ventilation rate and oxygen consumption rate were essentially independent of thermal radiation under all the environmental conditions investigated. However, heart rate increased appreciably with increases in thermal radiation provided the environment was already warm or hot. In the range between 70 and 100 F dry bulb, a 7 F increase in mean radiant temperature was found to elicit the same average increase in heart rate as a 1 F increase in dry bulb. For a cool environment the response tended to be reversed with the heart rate decreasing as the environment was made more comfortable by the addition of thermal radiation. Exercise shifted the point at which this reversal occurred toward lower temperatures. heat stress; heart rate; thermal intensity Submitted on July 16, 1964