Use of Thermoregulatory Models to Evaluate Heat Stress in Industrial Environments

Heat stress in many industrial workplaces imposes significant risk of injury to individuals. As a means of quantifying these risks, a comparison of four rationally developed thermoregulatory models was conducted. The health-risk prediction (HRP) model, the human thermal regulation model (HuTheReg), the SCENARIO model, and the six-cylinder thermoregulatory model (SCTM) each used the same inputs for an individual, clothing, activity rates, and environment based on previously observed conditions within the Portuguese glass industry. An analysis of model correlations was conducted for predicted temperatures (°C) of brain (T(Brain)), skin (T(Skin)), core body (T(Core)), as well as sweat evaporation rate (ER; Watts). Close agreement was observed between each model (0.81–0.98). Predicted mean ± SD of active phases of exposure for both moderate (T(Brain) 37.8 ± 0.25, T(Skin) 36.7 ± 0.49, T(Core) 37.8 ± 0.45 °C, and ER 207.7 ± 60.4 W) and extreme heat (T(Brain) 39.1 ± 0.58, T(Skin), 38.6 ± 0.71, T(Core) 38.7 ± 0.65 °C, and ER 468.2 ± 80.2 W) were assessed. This analysis quantifies these heat-risk conditions and provides a platform for comparison of methods to more fully predict heat stress during exposures to hot environments.