A new approach to predict heat stress and skin burn of firefighter under low-level thermal radiation

Abstract

A new approach was developed to predict the heat stress and skin injury of firefighter wearing protective clothing when exposed to low-level radiation. Heat flux profile under the clothing was generated by a bench top tester and applied to a proposed human thermoregulation model to simulate skin temperature at different body segments and core temperature. The resulting skin temperature was applied to calculate skin burn and the core temperature was used as the indication of heat stress to evaluate maximum exposure time. The predicted time to skin burn was compared with those calculated by the Pennes model. The results indicated that the new approach predicted lower skin temperature and longer time to 1st and 2nd degree burn compared with the traditional method, which was attributed to the change of blood flow, sweating rate, and body heat production. Furthermore, the new approach demonstrated that the time to skin burn at different body segments varied largely. The mean skin temperatures over-estimated the predicted time to 2nd degree skin burn than those simulated by the local skin temperatures at most body segments. Additionally, the maximum exposure time calculated by core temperature was longer than the time to 2nd degree skin burn simulated by skin temperature, indicating different physiological indicators would predict different safety exposure time. Generally, the proposed approach can assess physiological responses and maximum exposure time for firefighters as well as providing fundamental knowledge for the design of firefighter’s protective clothing.