Human responses to internittent work while wearing encapsulating chemical-biological protective clothing with personal HVAC

Human responses and safe work time limits for persons wearing the US Army's Self-Contained Toxic Environment Protective Ouot (STEPO) with personal CO2 scrubber 02 supply, and upper body cooling system were determined from human tests and human simulation modeling. STEPO is the Army's highest-level protective system. A rational thermal physiological model was assembled to simulate the responses and extend the human test results to other conditions. Comparisons between human and simulated responses include core and skin temperature, heart rate, thermal sensation, and water loss. Safe work time limits were until core temperature and heart rate exceeded 38.3 degrees C (101 degrees F) and 150 bpm.