Daijiworld Media Network – New Delhi

New Delhi, Apr 17: India is witnessing an early and intense spell of heatwave conditions, with temperatures crossing 40°C in several states in April itself. The India Meteorological Department (IMD) has issued multiple heat alerts, cautioning against prolonged exposure and advising special care for vulnerable groups.

Medical experts have warned that extreme heat is not just a seasonal discomfort but a serious health hazard that can affect multiple organs, including the heart, brain, kidneys and digestive system.

“Extreme heat is not just discomfort. It is a multi-organ stressor affecting the heart, brain, kidneys and metabolism,” said Dr Sanjay Verma, Senior Consultant in Internal Medicine at Fortis Escorts, Okhla.

He noted that early-season heatwaves are particularly dangerous as the body is not yet acclimatised. During April, the body is still in a winter-adjusted state, leading to delayed sweating, higher salt loss and less efficient blood circulation, increasing risks of dehydration, fainting and heatstroke.

Experts explained that at temperatures above 40°C, the body works significantly harder to maintain internal balance. Increased blood flow to the skin, continuous sweating and temperature regulation place added strain on the heart and kidneys, often causing fatigue even without physical activity.

Urban areas face additional risk due to the Urban Heat Island effect, where concrete structures, reduced greenery and vehicle emissions can raise local temperatures by 3–7°C. Nighttime heat further worsens health outcomes by preventing the body from recovering from daytime stress.

Doctors also warned that heat can impact digestion by reducing blood flow to the gut, leading to bloating, acidity and loss of appetite. Neurological effects such as irritability, anxiety and poor sleep have also been linked to dehydration and hormonal changes triggered by high temperatures.

Certain groups, including diabetes patients, chronic kidney disease patients and outdoor workers, are at higher risk of heat-related complications. The Indian Council of Medical Research (ICMR) has also flagged rising concerns over kidney damage among workers exposed to prolonged heat.

Experts cautioned that fans may not be effective in extreme heat conditions, especially when temperatures exceed body temperature or in high humidity, where sweat does not evaporate efficiently.

Heatstroke, they emphasised, is a medical emergency requiring immediate cooling measures, hydration if conscious, and urgent medical attention to prevent organ damage.

With heatwaves becoming more frequent and intense, experts have urged people to take preventive steps such as staying hydrated, avoiding peak sun exposure, and recognising early warning signs.