Objective To investigate the impact of ambient temperature on compensation costs due to work-related injuries, and to provide an evidence base about the economic benefits of developing workplace heat prevention strategies in a warming climate.

Methods Workers’ compensation claims obtained from SafeWork South Australia for 2000–2014 were transformed into daily time series format and merged with meteorological data. The relationship between temperature and compensation costs were estimated using a generalized linear model after controlling for long-term trends, seasonality, and day of week. A piecewise linear spline function was used to account for non-linearity.

Results A total of 4 64 139 workers’ compensation claims were reported during the 15 year period in South Australia, resulting in AU$14.9 billion dollars compensation payment. Overall, it is a reversed V-shaped temperature-cost association. A 1°C increase in maximum temperature was associated with a 1.1% (95% CI, 0.2%–2.0%) increase in daily injury compensation expenditure below 35.2°C. Specifically, significant increases of injury costs were observed in males (1.4%, 95% CI 0.3%–2.5%), young workers (3.0%, 95% CI 1.2%–4.9%), older workers≥65 years (2.4%, 95% CI 0.5%–4.4%), labourers (2.7%, 95% CI 0.5%–4.8%), machinery operators and drivers (3.5%, 95% CI 1.6%–5.3%) and the following industries: agriculture, forestry, fishing and hunting (12.3%, 95% CI 2.2%–23.3%); construction (7.8%, 95% CI 0.02%–16.3%); and wholesale and retail trade (2.4%, 95% CI 0.5%–4.4%). Costs for compensating occupational burns and ‘skin and subcutaneous tissue diseases’ increased by 3.1% (95% CI 1.2%–5.1%) and 2.7% (95% CI 0.1%–5.4%) respectively, with a 1°C increase in maximum temperature.

Conclusion There is a significant association between temperature and work-related injury compensation costs in Adelaide, South Australia for certain subgroups. Heat attributable workers’ compensation costs may increase with the predicted rising temperature.