SCENARIO revisited:: comparisons of operational and rational models in predicting human responses to the environment

1. This paper focuses on thermoregulatory modeling of individual variability in environmental extremes. 2. A great many worthwhile models do a reliable job describing the heat balance equation using a first principles approach by fitting operational equations or by using multi-node thermoregulatory servo-control models. 3. A soldier-based physiological/thermoregulatory model (SCENARIO (J. Therm. Biol. 22 (1997) 331) was enhanced using a probabilistic application of the Bayesian statistical paradigms in conjunction with Monte Carlo methods (SCENARIO-MC). 4. Coefficients improving the model include: algorithms for circadian and menstrual cycle offsets on the hypothalamic controller and an output depiction of correlation matrices between specific environmental and physiologic variables. 5. The model was found to be robust (based on root mean square deviations) particularly in physiological strain index prediction and able to predict individual esophageal and heart rate responses in women exposed to upward and downward thermal transients and wide perturbations of work/rest exercise in the heat while wearing protective clothing. (C) 2004 Elsevier Ltd. All rights reserved.