Occupational heat exposure in outdoor activities in building structures

Abstract In the construction industry, excessive heat exposure may cause thermal overload and damage workers' health. This study presents an analysis of the heat exposure of sixty-four workers performing activities on concrete slabs in the construction of concrete structures in buildings. In order to do that, the Wet Bulb Globe Temperature (WBGT) obtained from temperatures of natural wet bulb, dry bulb and black globe, measured on the slabs and analysed along with estimated metabolic rates was used for each work function, according to standards from International Standardization for Organization (ISO). The evaluation was made using criteria set by Brazilian laws, applying the Regulatory Standard Number 15 from the Ministry of Labour. The results showed there is a need to manage and adopt control measures, especially thermal rest breaks, aimed at body cooling to avoid diseases caused by heat. The study concluded that as the number of hours of thermal recovery rest is significant in relation to the number of total hours of work measured (39% for heavy activities and 20% for moderate activities), the adequate work/rest scheme can potentially affect the work pace in construction.