Introduction: Extreme heat has been associated with higher rates of mortality and morbidity. Excess cold and heat may also influence the occurrence of work-related injuries, but this hypothesis has not been previously explored in detail.
Objective: To analyse the relationship between ambient temperatures and work-related injuries in Spain.
Methods: Daily number of work-related injuries with at least 1 day of leave and daily maximum temperature were obtained for each Spanish province for the years 1994-2013. We estimated temperature–injuries associations with distributed lag non-linear models. We pooled them in a multivariate meta-regression. We calculated attributable injuries for cold and heat. Analyses were stratified by sex, age group and economic sector.
Results: The study included 15,992,310 work-related injuries. Overall, cold days were associated with an increase in work-related injuries of 4% (95% confidence interval (CI): 2%-6%), whilst days with extremely high temperatures presented an increase of 10% (95%CI: 8%-11%). Women, old workers and those working in transport were more vulnerable to cold temperatures. The highest associations for heat were observed among men, young workers and those working in agriculture. In total, 3.39% (95%CI: 2.96%-3.83%) of injuries were attributed to non-optimum temperatures (mean of 75 injuries per day). Most of the occupational injuries attributable to temperature were due to heat.
Conclusions: We found a consistent increase in work-related injuries associated with ambient temperatures. Specific preventive interventions may reduce occupational injuries among the most vulnerable groups of workers.