Heat, Health, and Harm: The Impact of Extreme Temperatures on Suicide

Abstract

"Climate change poses well-established risks to physical health, but little is known about its effects on mental health. I study the relationship between extreme tempera- ture exposure during summer months and suicide risk in the United States from 1989 to 2019 using comprehensive county-level data on all deaths by suicide and high-resolution satellite-based temperature measurements. I identify the causal effects of extreme heat on suicide by relating year-over-year fluctuations in county-level summer monthly average temperatures to fluctuations in suicide rates. I compare these effects across urban and rural areas and various population subgroups. My results indicate that an increase of one defined extreme heat day in a summer month leads to approximately 0.091 additional suicide deaths per million residents for summer months, with effects concentrated among men and working-age adults, demographic groups already characterized by elevated base- line suicide risk. This paper provides large-scale empirical evidence that climate-related extreme heat significantly elevates suicide risk, underscoring the urgent need for targeted public health interventions to mitigate climate-induced mental health burdens."