4 min readNew DelhiUpdated: May 4, 2026 04:25 PM IST
As large parts of India continue to battle intense heatwaves, many households instinctively turn to electric fans for relief. However, according to the World Health Organization (WHO), fans may actually become counterproductive, and even dangerous, when temperatures rise beyond 40°C.
Issuing guidelines to deal with the heatwave, the global health body stated on its website, “Use electric fans only when temperatures are below 40˚C / 104˚F. In temperatures above 40˚C / 104˚F, fans will heat the body.”
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.
But why is that?
Dr Rakesh Pandit, Senior Consultant and Head of Internal Medicine at Aakash Healthcare, explains that once the surrounding air becomes hotter than the body’s skin temperature, fans can end up adding heat to the body instead of cooling it.
“When you are in a hot environment, and the temperature of the air produced by the fan is higher than your skin temperature, the fan blows hot air over the skin and adds heat to the body instead of removing it,” says Dr Pandit.
How fans can become risky in extreme heat
Under normal conditions, fans help cool the body by increasing sweat evaporation. But during extreme heat, especially above 40°C, this mechanism may stop working effectively. Dr Pandit explains that prolonged exposure to very hot air can accelerate dehydration and place additional strain on the cardiovascular system. “Using fans at this temperature can increase dehydration, cause cardiovascular strain, and accelerate heat exhaustion or heatstroke,” he says.
The body then struggles harder to regulate its internal temperature, leading to symptoms such as dizziness, weakness, confusion, and, in severe cases, fainting. According to Dr Pandit, if the body fails to cool itself adequately, it can progress to a medical emergency such as heatstroke.
How to stay safe indoors during a heatwave
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Dr Pandit advises staying indoors during the hottest hours of the day and finding the coolest room in the house whenever possible. “If needed, leave your home for a few hours and spend time in a cooler environment,” he says.
He also recommends keeping windows closed during the daytime to block hot air and opening them only after sunset when temperatures drop. Curtains and blinds should remain shut during peak sunlight hours to minimise indoor heating.
Hydration, he stresses, is critical. “Drink plenty of fluids, preferably water, and avoid dehydration,” says Dr Pandit.
Eat light in summers (Photo: Freepik)
Other precautions include:
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- Wearing loose-fitting clothes made of natural fibres
- Avoiding heavy meals and strenuous exercise
- Taking cool showers
- Applying wet cloths to the body
- Using cross-ventilation after sunset
- Turning off unnecessary lights and electrical appliances that generate indoor heat
Who is most vulnerable during extreme heat?
“Elderly people, young children, outdoor workers and those with chronic conditions are most vulnerable,” says Dr Pandit. People living with heart disease, diabetes or kidney problems may find it harder for the body to regulate temperature effectively. Children, meanwhile, tend to dehydrate more quickly, while outdoor workers remain exposed to direct heat for prolonged periods, he adds.
Dr Pandit urges families to stay alert to early signs of heat exhaustion and heatstroke.
Symptoms that require immediate attention include:
- Extreme fatigue
- Headache
- Dizziness
- Nausea
- Muscle cramps
- Confusion
- Hot and dry skin
“If someone becomes disoriented or stops sweating, they need immediate cooling and urgent medical attention,” warns Dr Pandit.
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DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.