Background Despite increasing concerns about the health effects of climate change, the extent to which workers are affected by temperature increases is not well documented. This study aims to investigate the association between high temperatures and work-related injuries in Guangzhou, China.

Methods We used workers’ compensation claims to identify work-related injuries occurred in Guangzhou, China during 2011–2012. A time-stratified case-crossover study design was used to examine the association between temperatures and work-related injuries. Workers’ compensation claims data were transformed into time series format, merged with meteorological data and analysed using conditional Poisson regression models.

Results Overall, a 1°C increase in minimum temperature was associated with a 0.9% increase in daily injury claims. Specifically, the incidence rate ratio (IRR) for male workers and workers aged 25–45 were (1.011, 95% CI 1.002 to 1.006), and (1.018, 95% CI 1.014 to 1.022), respectively. Significant associations were also found between daily minimum temperature and risk of injury for fractures injuries, lower degrees of disability, manufacture, outdoor industries combined and small-sized enterprises, and between maximum temperature and injury for workers aged 25–45 and indoor industries combined. Larger effects were observed in the warm season for Guangzhou (1 June–31 October).

Conclusions There is a significant association between injury claims and temperature in Guangzhou, China, for certain industries and groups. This study provides valuable epidemiological evidence for policy-makers and relevant stakeholders for reducing potential effects of the projected increase in global average temperature due to climate change.