Scheduling Cycles of Work for Carrying under Heat Stress

Abstract

Five minutes of carrying loads uphill were assigned to three female and three male heat acclimated subjects. The carrying (75% ), both of which were performed under warm-humid T_db 36°C, T_wb 31°C, and hot-dry T_db 50°C, T_wb 25°C, ambient conditions. Thirty minutes of rest were allowed after each 30 minutes of work. The resting conditions were either the same as those for the working periods or under neutral ambient conditions. Judged by the rise in HR and in T_re, and setting the limits of T_re to 38°C during the walking, the schedule was adequate only when resting was under the neutral ambient conditions, it was partially adequate for resting under the hot-dry ambient conditions, but completely inadequate for resting under the warm-humid conditions.