Heatwave survival guide: stay cool without breaking the bank

With temperatures climbing and electricity bills soaring, here’s how to get through heatwaves without spending a fortune.

No, you haven’t tried everything to cope with extreme heat. Tired of keeping their shutters closed all day and living in the dark, some people in France are turning to a low‑tech workaround: a DIY product sold for €4 to €5 in home‑improvement shops. Demand has been so high that it’s now out of stock in many areas.

According to Actu.fr, Blanc de Meudon is seeing a real comeback as households look for ways to deal with summer heat. The idea is straightforward: mix the white powder with water and paint it onto sun‑facing window panes. Once dry, it creates an opaque film that reduces how much solar radiation gets into the home.

For years, this method was mainly used for agricultural greenhouses and commercial buildings. Now it’s winning over flat‑dwellers whose homes are difficult to cool, because it’s cheap, quick to apply, and just as easy to remove when the season ends. It’s often described as a temporary alternative to solar window film or air conditioning.

The product takes its name from the chalk quarries of Meudon in Hauts‑de‑Seine, where chalk-made largely of calcium carbonate-was mined for centuries for a range of craft and industrial uses. It’s not a miracle cure, but in periods of extreme heat it’s still an option worth considering.

Either way, it’s currently very hot in France-and it’s unlikely to get any better as summer progresses. If you’re struggling in the heat, you might be tempted to leave your shutters slightly open during the day to create a draught.

As Futura Science points out, that’s clearly not the right move, because shutters are crucial during a heatwave:

“This external protection is particularly important, because once the sun’s rays pass through the windows, they warm the walls, floors and furniture. The heat that builds up is then trapped indoors, creating what is known as a domestic greenhouse effect.”

So, when it’s hotter outside than it is indoors, you should not leave gaps open during the day.

The most effective weapon: natural ventilation

Once the temperature drops, ventilation is the ultimate low‑cost defence against heat. The simplest version is this: open your windows wide when it’s cool (usually at night), then close them again before the temperature rises. By setting up a through‑draught, you can cool your home without spending a penny.

Then the key is to hold onto that cooler air through the day by shutting every window, closing shutters, and drawing curtains to block the sun. Yes, your summer may feel a bit gloomy-but at least your poorly insulated home won’t sit at 30°C, and you won’t burn through money on electricity while an air‑conditioning unit runs flat out.

You can also use a fan, which is extremely effective when used properly. Put it in front of an open window in the evening so it pulls in the outdoor air as it starts to cool. A well‑known trick is to place a container filled with very cold water in front of the blades.

Evaporation can turn a basic tabletop fan that costs a few euros into a makeshift air‑cooling device, and you feel the cooling effect straight away. On top of that, a fan’s electricity use is more than 10 times lower than a portable air‑conditioning unit.

Another option is the wet‑sheet method found in traditional Maghreb architecture. Damp fabrics are hung in airflow to cool the surrounding air. A modern take is to soak an old sheet in cold water, wring it out slightly, and hang it in front of an open window. As it evaporates, it absorbs heat from the incoming air and can cut the temperature by 4 degrees.

Barricading your home against the sun

If you need an emergency fix and you’re on a very tight budget, aluminium foil might save you. Put it on windows that get direct sun with the shiny side facing outwards, effectively turning the glass into a reflective surface.

Compared with professional solar films sold at a high price, the cost is negligible. Even so, the best approach is still to close shutters and curtains before the sun returns, after airing the home with cool night air.

Hunt down hidden heat sources

Everyday electrical devices can act like radiators in disguise. A laptop can give off as much heat as a 150‑watt heater, and broadband routers also release a steady, often overlooked warmth. During heat peaks, routinely unplugging anything non‑essential can noticeably reduce the ambient temperature. So don’t hesitate to disconnect devices you aren’t using-the electricity savings will be even greater.

Also be careful with halogen bulbs, which turn a lot of electricity into heat. Modern LED lighting uses ten times less power and produces negligible heat.

It’s easy to forget, but cooking becomes a major issue during a heatwave. An oven can turn any home into a sauna, and hobs throw out intense heat. A winning approach is to cook very early in the morning while temperatures are still manageable, and to favour cold meals, salads and gazpachos that require no cooking.

Adjust your daily rhythm like hot‑climate countries

Mediterranean populations have spent centuries developing ways of living that suit intense heat. Their key habit? Completely reshaping the day to avoid the hottest hours. Get up at 6am to use the cool of the morning, take a nap from 2pm to 4pm when temperatures peak, then start again in the evening as the sun drops.

At rest, the human body generates far less heat and uses less energy. The Mediterranean siesta lines up precisely with the hours when outdoor temperatures hit their maximum. Of course, it depends on your work situation, but it’s a solid way to adapt your summer routine.

Choose your clothes strategically

Fabric choice directly affects how hot you feel. Polyester and synthetic fibres trap sweat and create a greenhouse effect on the skin. By contrast, linen, cotton and bamboo let your skin breathe and make natural evaporation easier.

Colour also matters physically. Light shades reflect sunlight, while dark colours absorb it and convert it into heat. Wearing a black T‑shirt at 35°C effectively turns you into a walking radiator.

Chilled clothing can bring immediate relief. Sheets, T‑shirts and underwear go into the fridge for thirty minutes before you use them. That instant coolness on the skin briefly offsets the heat in the room and helps you cope with temperature spikes. Otherwise, there’s always Sony’s personal air‑conditioning device-but it isn’t cheap.

Turn your nights into a refuge

Heatwave nights call for minimal, sensible bedding. Duvets and blankets should be replaced with a simple linen or cotton sheet. Natural fibres move moisture away from the body better than synthetic materials. In extreme cases, sleeping directly on the mattress avoids extra layers altogether.

A chilled pillow can work wonders for heat‑related insomnia. Put it in the freezer for an hour before bed to create a pocket of cool that lasts for several hours. This method can help you fall asleep even when night‑time temperatures exceed 25°C, and it doesn’t cost much.

A hot‑water bottle in summer sounds absurd, doesn’t it? But a frozen bottle filled with cold water and left in the freezer for two hours can release coolness in the bed for hours. The gradual drop in temperature supports falling asleep without a harsh thermal shock.

In summer, hydration is essential

Hydration during extreme heat follows some counter‑intuitive rules. Iced drinks, tempting as they are, don’t hydrate as well as lukewarm liquids. They can trigger thermal shocks that disrupt the body’s regulation. Fresh mint herbal tea or cucumber‑infused water, taken at room temperature, tends to cool you for longer.

Frequency matters more than volume. Drinking small sips very regularly helps the body absorb fluids efficiently. The body copes better with a steady supply than a single large intake. This keeps hydration levels stable, even in very high temperatures.

Food also plays an active role in cooling you down. Watermelon, cucumber, tomato and courgette contain over 90% water and perfectly complement what you drink. These water‑rich foods cool you from the inside while also replenishing the mineral salts lost through sweating.

Spend smart without breaking the bank

A few modest purchases can dramatically improve thermal comfort. An electric mister at €35 combines airflow with water evaporation to create a natural cooling effect. As long as you keep it nearby-because it won’t cool a large space-it delivers immediate relief.

A fan uses 50 watts versus 2000 watts for a portable air‑conditioning unit. Over three months of heavy use, the electricity saving exceeds €200. For people working from home-or stuck in offices where colleagues argue over the thermostat-a desk fan is a practical move.

With a personal fan, you can keep yourself cooler all day while using very little power. That’s it: you now have a full set of ways to cool down on the cheap.