Heat, Health, and Infrastructure: Infant Mortality in a Warming South and Southeast Asia (SSEA)

Climate change is intensifying the frequency and severity of heatwaves, with South and Southeast Asia (SSEA) among the most vulnerable regions. Using high-resolution climate and demographic data from 1960 to 2023 across eight countries, we examine the impact of in utero heat exposure on infant mortality. We find that each additional day with mean temperatures exceeding 30°C during gestation increases infant mortality by 1.78 deaths per 1,000 live births, relative to a 12-15°C reference range. The effects are more pronounced in rural areas and among populations lacking access to essential services such as healthcare, electricity, and transportation. These findings highlight the urgent need for climate-resilient infrastructure investments targeted at the most vulnerable communities to mitigate the rising burden of heat-related health risks.