Towards multi-scale and context-specific heat health risk assessment - A systematic review

Abstract

Frequent and continuous heatwaves cause significant heat stress on human health. The Heat Health Risk Index (HHRI) is a comprehensive assessment tool that helps identify heat risk levels across various regions. In this study, we systematically review 57 papers using PRISMA method. Our findings reveal limited attention to three key aspects: (1) consistency in indicator classification and selection, (2) context-specific subjects, and (3) adequate consideration of local-scale conditions. To bridge these gaps, we provide detailed explanations of how indicators can be classified based on their functional relationships with heat health. We also summarize methods for assessing indoor thermal environment at the local level and offer guidance for refining context-specific subjects. Additionally, we propose a cyclical framework for sustained HHRI assessments. This study concludes with implications for future HHRI assessments, calling for greater accuracy in technical methods and tailored assessments for specific spatiotemporal scales and contexts. It also encourages interdisciplinary collaboration, community engagement, and attention to compound climate risks.