Compound impact of heatwaves on vulnerable groups considering age, income, and disability.

The increasing frequency and intensity of heat waves due to climate change and urbanization have caused serious public health problems, especially in urban areas in which the heat effects are amplified by dense infrastructure and limited green space. This study examined the impact of heatwaves on vulnerable populations in Korean cities, focusing on how age, income, and disability are associated with higher health risks. In our study, we analyzed healthcare big data from 2010 to 2022 for seven major Korean cities. We employed a distributed lag non-linear model to assess the relationship between heat exposure and health outcomes, allowing us to quantify the compounded vulnerabilities due to socioeconomic and physical factors. The results showed that the association of compounded vulnerability was more pronounced in patients hospitalized through the emergency room, a severe health outcome, than in patients with mild health outcome such as outpatient visits for heat-related illnesses. The association of compounded vulnerability was particularly evident in the elderly population. These findings suggest the need for tailored heatwave preparedness strategies for vulnerable groups, contributing to the broader discourse on climate adaptation and public health resilience.