When weather wounds workers: The impact of temperature on workplace accidents

We study the effects of temperature on occupational health using administrative data on Swiss occupational accidents from 1996 to 2019. Our results imply that on hot days ( T m a x ≥ 30 °C) the number of occupational accidents increases by 7.4% and on ice days ( T m a x < 0 °C) by 6.3%, relative to mild days. We find that extreme temperatures cause an average of 2600 workplace accidents each year, costing CHF 91 million annually. We provide suggestive evidence for insufficient sleep on hot days as a mechanism. While extreme temperatures worsen occupational health, we observe limited labor supply adaption for most workers. • We study the impact of temperature on occupational health using Swiss accident data. • Both high and low temperatures cause an increase in workplace accidents. • Unlike hot days, ice days affect older workers more and cause more severe accidents. • Accidents on hot days are likely due to poor sleep, on ice days mainly due to slipping.