Background Exposure to high temperature has been linked to adverse effects including cardiovascular and renal functions. It was also proposed to diminish human performance capacity and increase accident risk. However, the effects of high temperature on occupational injury have not been extensively studied.

Objective The aim of this study was to determine the association between ambient temperature and occupational injury (OI) occurrence.

Material and Methods OI information was extracted from the National Health Insurance Research Database (NHIRD). Daily ambient temperature and relative humidity (RH) were obtained from the Taiwan EPA air monitoring station. The day of first time OI outpatient/emergency visits during 2006–2011 was used as the event day. The same weekdays of the month were used as the referent day. Time-stratified case-crossover design and conditional logistic regression was used to investigate the relationship between ambient temperature and OI outpatient visits, adjusting for RH.

Results There were 18 951 first time OI outpatient/emergency visits during 2006–2011. The odds ratio (OR) of OI outpatient visits associated with per interquartile range (7.7 degree centigrade) increase in ambient temperature of the same day (lag 0 day) was 1.15 (95% confidence interval, CI: 1.08–1.22). The ORs associated with lag1 (the day before visit day) to lag3 day was 1.13 (95% CI: 1.06–1.19), 1.11 (95% CI: 1.04–1.17), and 1.11 (95% CI: 1.02–1.14), respectively.

Conclusion Exposure to higher ambient temperature was associated with increased risk of OI outpatient visits.