Heat, home-based assault and domestic and family violence injuries: Evidence from hospital emergency department presentations.

BACKGROUND: Elevated temperatures have been associated with increased interpersonal violence, yet evidence from hospital, health-sector data remains limited. Guided by theories linking environmental conditions, social interactions and violence-related harm, this study examines home-based assault injuries, including domestic and family violence (DFV) related injuries, presenting to emergency departments (ED) in Victoria, the only state in Australia with mandatory recording of rich data on injuries enabling assessment of the relationship with heat exposure. METHODS: A retrospective analysis of the Victorian Emergency Minimum Dataset identified home-based assault injury presentations (2009-2024) and DFV-related injury presentations (2016-2024). Daily temperature and heat-stress metrics were derived from Australian Gridded Climate Data and time and place aligned with ED presentations. Associations between heat exposure and injury presentations were examined using generalized linear mixed models. RESULTS: A total of 28,637 home-based assault injuries and 10,194 DFV-related injuries were identified. Home-based assault injuries occurred more frequently during summer, weekends and holiday periods. After adjustment for temporal and contextual factors, unusually hot days were associated with a 5.7% increase in home-based assault injury presentations, while days exceeding 30°C were associated with a 6.7% increase. DFV-related injuries demonstrated similar temporal patterns, although associations with heat exposure were not statistically significant after adjustment for season. CONCLUSIONS: Higher temperatures were associated with increased presentations for home-based assault injuries. The findings indicate that environmental conditions are relevant to understanding violence-related injury in residential settings across metropolitan and rural communities in high-income countries and suggest that climate-related factors warrant consideration in violence prevention strategies, injury prevention initiatives and health service planning. By using robust ED data that is unlikely to be influenced by external factors, this study extends existing evidence beyond police-reported and recorded incidents, and provides insight into violence-related injuries requiring acute healthcare.