Follow TNM's WhatsApp channel for news updates and story links.
Twenty people have died and at least 4,853 people have suffered heatstrokes across India since March 1, according to data tabled in the Lok Sabha. Telangana recorded the highest number of heatstroke cases (915), followed by West Bengal (733), Chhattisgarh (660), and Andhra Pradesh (540).
Across the five southern states, Telangana recorded 915 heatstroke cases and two deaths, Andhra Pradesh reported 540 cases and four deaths, Karnataka registered 59 cases with no deaths, Kerala recorded 19 cases without any deaths, and Tamil Nadu reported two cases and one death.
The data was made available because the Union government has, for the first time, included heatwaves as a notified disaster for disaster relief funding, recognising the growing public health threat posed by extreme heat.
What is a heatwave?
A heatwave is a prolonged period of unusually high temperatures compared to what is normal for a region.
In India, the India Meteorological Department (IMD) declares a heatwave based on temperature thresholds.
Broadly:
In plains, a heatwave is declared when the maximum temperature reaches 40°C or more, along with a significant departure from normal temperatures. In coastal and hilly areas, the thresholds are 37°C and 30°C respectively.
IMD can also declare a heatwave if the maximum temperature touches 45°C or above, irrespective of the normal temperature.
The severity of a heatwave depends not only on air temperature but also on humidity, wind speed, and the duration of exposure.
What are the different heat-related illnesses?
Heat-related illnesses occur on a spectrum.
Heat cramps: Painful muscle spasms caused by heavy sweating and loss of salts.
Heat syncope: Fainting caused by prolonged standing or sudden exposure to heat.
Heat exhaustion: Characterised by heavy sweating, weakness, dizziness, nausea, headache and dehydration. Body temperature usually remains below 40°C.
Heatstroke: Symptoms include confusion, seizures, loss of consciousness, hot skin, and very high body temperature.
What is heatstroke?
Heatstroke is the most severe form of heat-related illness.
According to the World Health Organization (WHO), prolonged exposure to high temperatures or strenuous physical activity can overwhelm the body's ability to regulate its temperature, and result in heatstrokes.
Under such circumstances, the body's cooling mechanisms may fail, making the core body temperature rise to 40°C (104°F) or higher, causing damage to the brain and other vital organs.
Unlike heat exhaustion, which can often be reversed with rest and hydration, heatstroke is a medical emergency. Without immediate treatment, it can lead to permanent disability or death.
What does data show?
Minister of State for Home Affairs Nityanand Rai told the Lok Sabha that a total of 4,853 heatstroke cases and 20 confirmed deaths have been reported across the country between March 1 and July 26.
Among all states, Maharashtra recorded the highest number of confirmed heatstroke deaths at 11, followed by Andhra Pradesh with four, Telangana and Odisha with two each, and Tamil Nadu with one.
Responding to a question on whether the Union government was considering declaring heatwaves as a natural disaster, Rai said the Ministry of Home Affairs has, based on the recommendations of the 16th Finance Commission, included heatwaves and lightning in the list of notified natural calamities under the operational guidelines for the State Disaster Response Fund (SDRF) and National Disaster Response Fund (NDRF) for the 2026-31 award period.
He informed the House that a policy framework for providing relief assistance through SDRF and NDRF is now in place, and heatwave mitigation projects are also eligible for support under the Disaster Mitigation Funds.
However, differences in the methodology used for confirming heatstroke deaths have resulted in discrepancies in the data provided by various sources. For instance, while the Telugu media noted 34 and 51 heat-related deaths on May 22 and 23 respectively, the Telangana revenue department said that 16 people had died of heat in the summer of 2026. The state disaster management department offered a far smaller fatality count, stating that only 8 persons had died of heat-related illnesses in the state as of May end.
What has the government done?
Minister Rai said the Ministry of Health and Family Welfare, through the National Programme on Climate Change and Human Health (NPCCHH), has been implementing heat-health interventions in line with the National Action Plan on Heat Related Illness. Heat advisories have been issued to state health departments, while customised colour-coded advisories based on IMD heatwave warning bulletins are disseminated to states and districts to improve preparedness and response.
Rai also said the National Heat-Related Illness and Death Surveillance (NHRIDS) has been activated across more than 51,000 reporting units covering primary health centres and higher-level hospitals across the country.
The National Disaster Management Authority (NDMA) has issued national guidelines for the effective management of heatwaves and prepared guidelines for Heat Action Plans, enabling heatwave-prone states and Union Territories to strengthen preparedness and response mechanisms.