Spatial Differentiation and Equity of Urban Heat Health Risks from the Perspective of 15-Minute Life Circle

Intensified climate change-induced urban heat threatens urban residents’ health and triggers climate equity gaps, with people over 65 and under 18 as core high-risk groups. This paper adopts the Vulnerability‑Sensitivity‑Adaptability (VSD) assessment framework to quantify urban heat health risks. It retrieves high-resolution land surface temperature data and constructs indicators incorporating vulnerable age populations and urban green resources. Using Geographic Information System (GIS) network analysis, the study delineates 15-minute life circles and analyze spatial differentiation of heat health risks, while applying the Gini index to measure intergroup climate equity. The study found that the old urban area of Nanjing has a high exposure rate, high vulnerability, and low adaptability, which belongs to the high-risk and low-adaptation area, while the new urban area is on the contrary. The elderly and underage population bear a higher proportion of climate risks, but they have a lower level of preventive measures, and group climate equity needs to be improved urgently. This study helps to identify risk-adaptation mismatch areas, understand the hot risk adaptability of vulnerable groups, and provide insights and a theoretical basis for coping with global warming, accelerating high temperature adaptability, ensuring the needs of vulnerable groups, and improving urban climate equity.