Gender-based violence (GBV) remains a critical threat to women's safety and equality worldwide, yet the role of climate and environmental stressors in shaping violence against women remains underexplored, particularly in developed countries. This study identifies the causal impact of short-run temperature fluctuations on GBV in Italy using ten years of province-level data (2013-2022) on helpline calls and femicides and a two-way fixed effects estimation strategy. We find that higher temperatures increase both help-seeking behavior and lethal GBV. Accounting for nighttime temperatures shows that elevated minimum temperatures are particularly consequential relative to daytime heat. Heterogeneity analyses indicate that temperature effects are not uniform across provinces, with evidence of differential responses along selected dimensions related to adaptation and socio-economic context. Overall, the results highlight the relevance of considering climate-related stressors within violence prevention and social protection frameworks, even in high-income countries.