A peer-reviewed study reports that heatwaves in India coincide with elevated ground-level ozone, which is linked to increased cardiac deaths. The study finds that surface ozone levels reach about 85–110 μg/m³ in northern India during heatwaves and that concentrations exceed the World Health Organization (WHO) guideline threshold of 70 μg/m³ across every region of the country. The research also compares mortality during heatwave periods with preceding days. For 2024, it estimates that there are about 830 more reported deaths during the heatwave than on the days immediately beforehand, attributing the increase to the combined effects of heat exposure and ozone pollution. By focusing on the interaction between extreme temperatures and air quality, the study highlights a health risk that can worsen during seasonal heat events. The findings are based on the reported pattern of ozone rising during heatwaves and the corresponding change in cardiac-related mortality statistics during those periods.