ISLAMABAD: A new study published in the academic journal Frontiers in Environmental Health reveals that India is among the world's most heat-exposed nations, with a single day of severe heat potentially causing approximately 3,400 deaths, while a five-day heatwave could result in nearly 30,000 fatalities nationwide.
Underreporting of Heat-Related Deaths
The peer-reviewed research, conducted by Piyush Narang and Ashok Gadgil of UC Berkeley's Goldman School of Public Policy, indicates that official heat-related death figures capture only a fraction of the true toll. The all-India heat-related excess mortality reported in the press and by government agencies remains around 800 per year. This means a single extreme day kills more than four times what officials count across an entire year.
"Heat mortality remains substantially undercounted," the study states, adding that many deaths triggered or worsened by extreme temperatures are often recorded under other medical causes rather than heat exposure itself.
Methodology and Findings
To arrive at accurate estimates, researchers combined findings from a 2024 multi-city epidemiological study covering ten Indian cities with district-level mortality records from the Civil Registration System and 2024 population projections. They matched each of India's 765 districts to the most climatically similar study city and used the city's established heat-mortality relationship to estimate excess deaths from one extreme-heat day and from five consecutive extreme-heat days.
"Our results suggest that even a single day of extreme heat yields thousands of excess deaths, and a multi-day heatwave results in tens of thousands of excess deaths," the researchers wrote.
Regional Disparities
The study found that the burden is unevenly distributed, with populous northern states experiencing the highest mortality rates. Uttar Pradesh alone was estimated to account for more than 8,000 excess deaths, followed by Bihar (3,615), Madhya Pradesh (2,964), Rajasthan (2,664), and Gujarat (2,354). According to the study, these five states together hold 43% of India's population but account for more than 60% of the projected national heat mortality.
