Prediction of body temperatures during exercise in flying clothing.

A mathematical model has been used to describe experimental results for core and skin temperatures in subjects undergoing a rest/activity cycle in two aircrew clothing assemblies at two environmental temperatures (wet bulb, globe temperature (WBGT) indices of 25.9 and 28.9 degrees C). The model presented compares well with published data for subjects in standard aircrew equipment assemblies. Aircrew flying at a WBGT of 28.9 degrees C in chemical defence clothing may reach an unacceptable level of mean body temperature within 40 min and deep body temperature will rise at 1 degree C.hr-1. To prevent deterioration in flying performance during repeated sorties, an alteration in the work/rest activity pattern or the introduction of effective cabin or personal conditioning systems may be required,