Assessing heat-related health risks is important for sustainable urban development. Although fine-scale infor-mation (e.g., at the community/neighborhood or city block level) is ideal for identifying and mitigating these risks, previous studies have preferred to work at the administrative unit level. High-resolution Local Climate Zone (LCZ) maps, i.e., maps of urban "zones" with different microclimates, could help to standardize the analyzing units. In this study, we proposed an LCZ-based risk assessment approach for this purpose. First, an LCZ map of the study site (Changzhou, China) was generated using multisource big data and machine-learning techniques. Next, Crichton's Risk Triangle framework, based on the hazard-exposure-vulnerability risk compo-nents, was employed to estimate heat-related health risks. Finally, the relationship between LCZ types and heat -related health risk levels was quantitatively analyzed in detail. The results indicated that at least 60% of LCZ1-5 (compact high-/mid-/low-rise, open high-/mid-rise areas) were designated as high-risk areas, while heat hazard mitigation and climate adaptation strategies in urban planning would benefit more from LCZ 6 (open low-rise). This study, based on the LCZ concept, shows the risk difference at the community level, and can be used for informing and implementing area-level urban planning strategies. It could contribute to global heat-related health risk analysis, since the LCZ is a globally consistent system for urban microclimate analysis.