Modeling Human Thermoregulation as a Means of Evaluating Heat Stress Events

This paper presents methodology for predicting body core temperature using the ASHRAE two-node thermoregulation model. Predicted changes in core temperature can be used to certify that, during a heat stress event, the temperature and humidity within an aircraft will not exceed values that are hazardous to the occupants. The use of ASHRAE model was validated by comparing its predictions to experimental data for subjects that were exposed to hot (33° to 48°C) environments. The model has been used to predict body core temperature in the cockpit and cabin during three different environmental ventilation system failure simulations for an aircraft that uses atmospheric air from the ram air duct in the event of a dual pack failure.