Relationships Between Extreme Ambient Temperatures, Neighborhood Structural Deprivation, and Fatal Police Violence: A Case-Crossover Analysis.

Police violence is increasingly recognized as a public health crisis, disproportionately affecting Black, Indigenous, and other communities of color due to long-standing patterns of racialized surveillance and disinvestment. Environmental stressors such as heat have also been linked to increased aggression, stress reactivity, and violence, suggesting that as climate change drives more frequent and intense extremes in temperature, these conditions may amplify existing risks of fatal police encounters. This study evaluated whether extreme ambient temperatures were associated with fatal police violence and whether structural neighborhood deprivation modified this relationship. Our nationwide case-crossover analysis examined daily maximum temperature and fatal police violence in the United States (2013-2024) using data from Mapping Police Violence. We estimated odds ratios across percentiles of the temperature distribution and analyses were stratified by neighborhood-level measures of deprivation, using Index of Concentration at the Extremes metrics for education, income, racialized income, and homeownership. Our main analysis revealed that compared to the median temperature (23.5 °C), the odds of fatal police violence at the 5th temperature percentile were reduced by 12% (95 percent CI: 0.806 to 0.955), while the odds at the 99th percentile were increased by 11% (CI: 1.037 to 1.185). While there was limited evidence of effect modification by neighborhood deprivation metrics, we found neighborhoods with higher levels of deprivation were disproportionately burdened by fatal police violence. These findings highlight the importance of temperature as a determinant of fatal police violence, suggesting that policies that address neighborhood deprivation and fatal policing may be needed on a warming planet.