A computer model of human thermoregulation for a wide range of environmental conditions: the passive system. Fiala, Dusan, Kevin J. Lomas, Martin Stohrer. a)Institute of Energy and Sustainable Development, De Montfort University Leicester, The Gateway, Leicester LE1 9BH, UK and b)HfT Stuttgart, Fachbereich Bauphysik, Schellingstr. 24, 70174 Stuttgart, Germany
APStracts 6:0260A, 1999.
A dynamic model predicting human thermal responses in cold, cool, neutral, warm and hot environments is presented in a two-part study. This, the first, paper is concerned with aspects of the passive system: 1) modelling the human body, 2) modelling heat transport mechanisms within the body and at its periphery, and 3) the numerical procedure. A companion paper will describe the active system and compare the models predictions with experimental data and the predictions of other models. Here, emphasis is given to a detailed modelling of the heat exchange with the environment: local variations of surface convection; directional radiation exchan[sim] ge; evaporation and moisture collection at the skin; and the non -uniformity of clo[sim] thing ensembles. Other thermal effects were also modelled: the impact of activity le[sim] vel on work efficacy; and the change of the effective radiant body area with posture. A stable and accurate hybrid numerical scheme was used to solve the set of time-in[sim] dependent _conduction_- and time-dependent _blood_ -matrices. Predictions of the pas sive system model are compared with available analytical solutions for cylinders and spheres and show good agreement and stable numerical behaviour even for large time steps. (Accepted for the Modeling in Physiology section)

Received 19 July 1996; accepted in final form 27 May 1999.
APS Manuscript Number A687-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 14 June 1999