A recent study underlines the dangers of these worsening highs. It estimates that a single day of extreme heat causes approximately 3,400 excess deaths nationally in India.

A five-day heatwave is linked to nearly 30,000 extra deaths, according to the paperpublished in the Frontiers in Environmental Health journal last month.

These heatwaves are becoming more frequent, longer and more intense as climate change – driven by the burning of fossil fuels – pushes global temperatures higher. The past 11 years, from 2015 to 2025, were the hottest on record, according to the World Meteorological Organization (WMO).

Official counts of heatwave deaths in India are much lower – between 500 and 1,500 annually nationwide – but experts warn these are grossly underestimated. This is due to a lack of uniform tracking and a failure to take indirect impacts into account, such as the exacerbation of underlying health conditions.

The study is the first to attempt to rectify this by providing detailed numbers for all of India’s 765 districts. It also captures the full hidden impact of heat by taking into account all excess deaths during a heatwave, rather than only those directly attributable to heatstroke or heat-related disasters.