Heatwaves in India: What They Are and How to Keep Your Family Safe

In Tamil Nadu we joke that we have three seasons: hot, hotter and hottest. But the heat of recent summers is no joke. Afternoon roads feel like ovens, power cuts make nights sleepless, and every year we read news of people collapsing from heat stroke.

Heat is a silent danger because we underestimate it. Let us understand what a heatwave really is, and what we can do at home to stay safe.

🌡️ What Exactly Is a Heatwave?

A heatwave is not just “a hot day”. The India Meteorological Department (IMD) uses specific rules. In simple terms, for the plains:

• The maximum temperature should be at least 40°C, and
• it should be about 4.5°C or more above normal for that place and time of year, or
• the actual temperature crosses 45°C, whatever the normal is.

For coastal areas like Chennai, the threshold is lower — around 37°C with a similar jump above normal — because humid coastal heat is harder for the body to handle. Hilly areas have a threshold of 30°C. When temperatures go even further above normal, IMD calls it a severe heatwave.

IMD issues colour-coded warnings — green, yellow, orange and red — so it is worth checking the forecast during summer instead of guessing.

🥵 Why Heat Is So Dangerous

Our body cools itself mainly by sweating. When sweat evaporates, it takes heat away. But when the air is very hot — or very humid, as on our coast — sweat doesn’t evaporate well. Body temperature keeps rising.

The result can range from mild to life-threatening:

• Heat rash and cramps — itchy skin, painful muscle spasms.
• Heat exhaustion — heavy sweating, weakness, dizziness, headache, nausea.
• Heat stroke — very high body temperature, confusion, hot dry skin (sweating may stop), fainting or fits. This is a medical emergency.

Those most at risk are elders, babies and young children, pregnant women, people with heart, kidney or diabetes problems, and outdoor workers like construction labourers, delivery partners and traffic police.

💧 Simple Ways to Stay Safe

1. Drink water even if you are not thirsty. Thirst comes late. Keep a bottle with you. Use our water intake calculator as a rough guide.
2. Use home drinks. Buttermilk (mor), lemon juice with a pinch of salt, tender coconut water, and ORS help replace salts lost in sweat.
3. Avoid the harshest hours. Try to stay indoors roughly between 12 noon and 3 pm, when the sun is strongest.
4. Dress light. Loose, light-coloured cotton clothes, a cap or umbrella, and footwear when stepping out.
5. Limit tea, coffee, alcohol and very sugary drinks in peak heat — they don’t hydrate you well. My article on rethinking our drinks has more on this.
6. Eat light. Fresh fruits like watermelon, cucumber and curd rice are better than heavy, oily meals.
7. Never leave children or pets in a parked car, even for “just two minutes”.

🏠 Keeping the Home Cooler

• Close curtains or use bamboo blinds on sun-facing windows during the day.
• Open windows in the early morning and late evening to let cooler air in.
• Wet cotton cloth near a window or fan cools the air a little — an old trick that still works.
• White or reflective paint on the terrace can reduce heat entering top-floor homes.
• Plants and trees around the house give real shade over time.

🚑 If Someone Shows Signs of Heat Stroke

Act fast. While you arrange medical help (call 108 for an ambulance in most states):

1. Move the person to a shaded, cool place.
2. Loosen tight clothing.
3. Cool the body with wet cloth, sponging or fanning — especially the neck, armpits and groin.
4. If the person is conscious and able to swallow, give small sips of water or ORS.
5. Do not give anything by mouth if they are confused or unconscious.

“In summer, a glass of water offered to a stranger can be a small act of rescue.”

🤝 Look Out for Others

Keep a pot of drinking water outside your gate for delivery workers and passers-by. Check on elderly neighbours who live alone. If you employ house help or drivers, give them breaks and water in the afternoon. Many towns and districts now have heat action plans with cooling shelters and water points — find out what your local body offers.

Scientists expect heatwaves to become more frequent as the planet warms, and climate patterns like El Niño can make some summers hotter still. Preparing is no longer optional.

✨ Takeaway

Heat doesn’t make noise, but it can be deadly. Drink water, avoid the midday sun, keep homes cool, and watch over the most vulnerable. Small habits, practised every summer, keep the whole family safe.

This article is for general awareness and is not medical advice. In an emergency, seek medical help immediately.