Interactive Effects of Heat Load and Respiratory Stress on Work Performance of Men Wearing CB Protective Equipment

Abstract : Interaction between the effects of respiratory stress and thermal stress has been objectively identified. Analyses of data on distance run, percentage of inspiration at termination, and respiration rate at termination indicate the low value of resistance, 0.1 mm H2O-min/liter, to be the point at which interaction occurs. The heat load value causing interaction is somewhat equivocal. A model has been proposed which is consistent with our results and which defines the stress limitations for different rates of exercise. With the use of this model, the value of 0.1 mm H2O-min/liter has been objectively defined as the minimum effectual protective mask airflow resistance. Evidence is presented for exhalation time as the index of the respiratory stress limitation.