Heatwaves are extreme weather events that can have severe impacts on human health. As global temperatures rise due to climate change, the frequency, duration, and intensity of heatwaves are expected to increase. To better inform planning and prevention, high risk regions/districts must be identified in advance. This work focuses on the state of Karnataka, to assess the heatwave occurrence and develops a Heatwave Health Risk Index (HHRI) at district level.

A comprehensive IPCC framework of climate change risk assessment methodology incorporating hazard, exposure, and vulnerability was employed to develop HHRI under current climate change scenario. Among the crucial determinants influencing the HHRI, 11 indicators were selected, encompassing heatwave occurrence, diurnal temperature ranges, population density, outdoor labour population, population commuting on foot, number of medical institutions, green cover, elderly population (60+ years), disabled population, Multidimensional Poverty Index (MPI), and Health Index (HI). Both primary and secondary data from reliable sources were used in this study. Collected data were analysed and spatially mapped.

The data analysis revealed that districts in the northern region of Karnataka generally had higher hazard and exposure indexes. Notably, Bidar, Gulbarga, Dharwad, and Gadag showed very high HHRI values, indicating the highest heatwave health risks. On the other hand, districts like Kodagu, Dakshina Kannada, Udupi, and Uttara Kannada exhibited the lowest HHRI values, indicating lower risks. Overall, this study contributes valuable insights into the regional variation of heatwave health risks in Karnataka, enabling policymakers to prioritize and implement targeted interventions to mitigate the impacts effectively.