Urban Heat, Mortality, and Economic Costs : Evidence from Bangkok, Thailand

Urban heat is an increasingly important public health risk, yet empirical evidence on its health and economic impacts remains limited, particularly for rapidly growing tropical megacities. This study aims to provide an operational basis for urban planning and investment decisions by quantifying heat-induced health burdens across Bangkok’s 50 amphurs (districts) and the associated citywide economic costs. The study translates heat exposure into excess deaths at the amphur level by employing a city-specific temperature-mortality relationship along with data on population and mortality. It then converts the number of excess deaths to monetary terms based on the Value of a Statistical Life. On average, an estimated 593 deaths per year were attributable to higher-than-optimal temperatures during 2016–18, amounting to 1,778 deaths over the three-year period, with substantial variation across amphurs and months. This represents a significant public health burden, comparable in magnitude to road traffic fatalities in Bangkok, which claimed 614 lives in 2021. In monetary terms, heat-related excess mortality is estimated to account for 0.1–0.7 percent of Bangkok’s gross provincial product during 2016–18 (between 7.76 billion and 46.97 billion baht in current prices), exceeding the Bangkok Metropolitan Administration’s public health budget in 2020 (6.733 billion baht). This study concludes that heat exposure in Bangkok is associated with a substantial public health burden and meaningful welfare losses. The pronounced spatial and temporal heterogeneity in estimated impacts underscores the importance of place-specific interventions and prioritization of higher-risk amphurs. Quantifying heat-related impacts in monetary terms can support more robust cost–benefit analysis and inform evidence-based urban planning and investment decisions for heat mitigation and adaptation.