ABSTRACT
Heat stress contributes to metabolic heat production and sweating that may lead to discomfort, heat exhaustion, heat illness and loss of workers’ performance. Sweating is closely related to heat stress because core (Tcore) and skin (Tsk) temperatures are the main inputs to the thermoregulatory process in which sweat increases with body heat production (see [1] and [2]). Thus, a quantitative composite measurement of sweat loss has been developed by integrating climatic, physical and personal factors (Fig. 1) based on heat balance equations (see [3] and [4]). It has also been assumed that sweat production should correlate with the Ereq and Emax in order to keep the body heat balanced [5]. Based on this, a comprehensive model, for example, MSL = 27.9Ereq(Emax)−0.455 (g/m2h), has been used as a function of climatic condition, metabolic rate and work clothing [6]. This equation is derived from experimental exposures under controlled laboratory conditions, and is valid within a certain range (Ereq = 50…360 W/m2 and Emax = 20…525 W/m2). In order to be applicable in an outdoor environment, this mathematical equation has been adjusted to show a high correlation between the measured and expected values. Using the new model as a predictive heat balance equation, this study followed the estimation of sweat loss, which also indicates heat stress. Thus, the aim of this paper is to identify heat stress and verify it by adjusting the measured and predictive values of sweat loss in hot working conditions (HWC). The results reveal that work tasks in HWC seem to be stressful in tropical developing countries because of excessive heat load. In this connection, occupational safety and health (OSH) measures are suggested which are yet to be implemented in many tropical developing countries. Factors affecting the heat load on the workers in HWC. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780367812027/499b2676-17a6-4805-9fd8-78c8baf0b813/content/fig3_1.tif"/>
