Unveiling Heat Vulnerability Across India: A Multi-Method Analysis of District-Level Indicators in the Context of Climate Change.

According to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment (AR6) report, continued global warming and changes in the climate system will increase the likelihood of severe impacts on both people and ecosystems. Accurately assessing the impacts of extreme heat has become a pressing research challenge, particularly as heatwave and heat-health warning systems evolve. Identifying key indicators of heat-related mortality and morbidity is critical to mitigating these impacts. Despite its importance, a comprehensive national-level assessment of heat vulnerability in India remains underdeveloped, leaving a significant research gap in heatwave disaster management. Moreover, the notion of vulnerability has evolved continuously, especially with updates in IPCC assessments, and it varies across communities, societies, regions, and countries and changes over time. This study analyses district-level (640 districts) vulnerability in India based on multiple methodologies, including the Simple Average Method, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), the Principal Component 1 (PC1) method, and the Cutter and Finch (2008) approach, supported by a refined set of vulnerability indicators. Key data sources include the Census of India (CoI), alongside other datasets. The spatial distribution of vulnerability indicates that North and Eastern India are the most susceptible to heat related vulnerability. In the context of India’s agrarian economy, this mapping is crucial for supporting the livelihoods of farmers and outdoor workers, who are among the most susceptible to extreme heat events. This study underscores the urgent need for a robust, methodologically comprehensive national heat vulnerability assessment to guide targeted policy interventions and enhance resilience against the escalating threat of extreme heat in India. The vulnerability map developed will serve as a foundational tool for creating a comprehensive risk map by integrating hazard and exposure, enabling targeted interventions to mitigate heat-related risks.  Keywords: Heatwave, Heat Stress, India, IPCC, Vulnerability.