Predicting heat-related health risks in rapidly urbanizing cities

Rapid urbanization and climate change are intensifying heat exposure in cities, turning extreme heat into a persistent and unevenly distributed public health risk. Conventional heat risk assessments often rely on temperature thresholds or surface heat mapping, but these approaches may overlook the biological sensitivity, socio-spatial inequality, urban form, health-system capacity, and governance conditions that determine who is harmed, where, and why. This paper presents a framework-oriented integrative synthesis that develops the Urban Heat–Exposure–Health (UHEH) axis as a conceptual and translational structure for organizing heat-health risk in rapidly urbanizing cities. Drawing on evidence from urban climate science, environmental epidemiology, public health, spatial analytics, heat vulnerability research, and urban governance, the framework links urban form, thermal exposure, demographic sensitivity, social vulnerability, health outcomes, and institutional response pathways. Rather than presenting a fully implemented predictive model or empirical validation study, the paper clarifies the data streams, analytical relationships, equity indicators, and validation requirements needed for future operational heat-health modeling. The UHEH framework identifies how satellite, in situ, and modeled thermal data can be combined with socio-spatial vulnerability indicators, urban morphology metrics, and health outcome proxies such as emergency department visits, hospital admissions, ambulance calls, and mortality records. It also maps key mechanistic pathways, including cardiovascular strain, dehydration, renal stress, air-pollution interactions, sleep disruption, and cumulative exposure. However, the framework is not presented as a validated predictive model; rather, it provides a structured basis for future empirical testing, local calibration, comparison with existing heat vulnerability approaches, and validation against observed health outcomes. By integrating exposure, vulnerability, biological response, and governance into a single analytical pathway, the framework supports the design of heat-health early warning systems, real-time dashboards, policy triggers, targeted cooling interventions, and equity-centered adaptation strategies. The paper contributes a structured foundation for future empirical testing, model calibration, cross-city comparison, and decision-support development aimed at reducing heat-related morbidity and mortality in rapidly urbanizing cities. Clinical trial number: Not applicable.