Heat stress and the labour force

Heat stress affects the health of workers through physiological and behavioural responses, in turn, affecting the labour force through impacts on labour supply, labour productivity and labour capacity. In this Review, we explore the extent to which heat stress affects the labour force and discuss the corresponding occupational health and economic impacts. The relationship between labour force outcomes and temperature is largely nonlinear, declining sharply beyond peak thresholds. Observed and projected labour losses are heterogeneous across regions, sectors and warming levels. High-exposure sectors such as agriculture and construction are projected to experience the greatest losses under future warming, with ~33%, ~25% and ~18% declines in effective labour across Africa, Asia and Oceania, respectively, under a 3 °C warming scenario. Labour losses are also expected in low-exposure sectors such as manufacturing and utilities, but Northern Europe tends to benefit in the short run. These collective heterogeneous labour impacts lead to considerable reductions in global gross domestic product (GDP) and welfare, with projected GDP losses of 5.9% in South Asia and 3.6% in Africa. Improved local-scale exposure–response functions and incorporating adaptation into economic models are required to advance understanding of heat stress impacts on labour. Rising temperatures are increasing heat stress, in turn, influencing the labour force. This Review outlines observed and projected changes to labour supply, labour productivity and labour capacity, offering insight into their macroeconomic impacts and adaptation opportunities.