Heat stress in outdoor manual workers in East Africa.

Abstract Use of the Predicted 4-hour Sweat Rate (P4SR) to determine tolerable limits of heat stress in outdoor work is examined, using data from a training centre near Dar es Salaam, Tanzania. The proportion of days with heat stress exceeding a tolerable limit for 3 hours or more was assessed over a 14-month period, and mean rest allowances calculated. The calculation of maximum energy expenditures within the tolerable limit, and use of ordinary climatic data is considered in order to derive a simple guide to heat stress and rest allowances in outdoor work.