How to survive heatwaves without breaking the bank

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

Right now, it’s blisteringly hot in France - and it’s unlikely to get any better as summer goes on. If, like us, you’re feeling genuinely overwhelmed by the heat, you may be tempted to leave your shutters slightly open during the day to create a draught.

As Futura Science points out, that’s clearly not a good idea, 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 accumulated this way then remains trapped inside, creating what is known as a domestic greenhouse effect."

So, when it’s hotter outside than it is indoors, you should never leave gaps open during the day.

The most effective weapon: natural ventilation

Once the temperature drops, ventilation is the single best low-cost defence against overheating. The simplest version of the method is straightforward: open your windows wide when it’s cool (usually at night), then close them again before temperatures rise. By creating a through-draught, you can bring down the indoor temperature without spending a penny.

After that, the goal is to keep the cool air in throughout the day by closing all windows, shutters and curtains, so they form a barrier against the sun. Yes, your summer may feel a bit dark indoors - but at least your poorly insulated home won’t be sitting at 30° while your air conditioning runs flat out and your electricity spend spirals.

You can also use a fan, which is extremely effective if you use it properly. Set in front of an open window in the evening, it pulls in outdoor air as it starts to cool. The insider trick? Put a container filled with very cold water in front of the blades.

Evaporation turns a basic tabletop fan that costs only a few euros into a DIY air conditioner. You feel the cooling effect straight away - and a fan uses more than 10 times less electricity than a portable air conditioner.

There’s also the wet-sheet technique, drawn from traditional Maghreb architecture. Damp fabrics are hung in airflow to cool the atmosphere. 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 the water evaporates, it absorbs heat from the incoming air and can reduce the temperature by 4°C.

Barricade your home against the sun

If you’re in an emergency situation and have very little budget, aluminium foil could genuinely save you. Fixed to sun-facing windows with the shiny side pointing outwards, it effectively turns the glass into a reflective mirror.

Compared with professional solar films sold at a steep price, this workaround costs next to nothing. Even so, the best approach is still to close shutters and curtains before the sun returns - after you’ve aired the place with cool night air.

Hunt down hidden heat sources

Everyday electrical devices behave like radiators in disguise. A laptop can put out as much heat as a 150 watts heater, and internet routers also release a steady, often overlooked amount of heat. During peak heat, unplugging anything non-essential makes a noticeable difference to the room temperature. So don’t hesitate to disconnect devices you’re not using - the electricity savings will be even greater.

Also watch out for halogen bulbs, which convert a lot of electricity into heat. Modern LEDs use ten times less power and give off negligible heat.

It’s easy to overlook, but cooking becomes a major issue during a heatwave. An oven can turn any home into a sauna, and hobs give off intense heat. The best strategy is to cook very early in the morning while it’s still bearable, and to favour cold meals - salads and gazpachos that require no cooking at all.

Adjust your routine like people in hot countries

Mediterranean populations have spent centuries developing a way of life that suits intense heat. Their key? Completely reshaping the day to avoid the hottest hours. Get up at 6 h to take advantage of the morning cool, take a siesta from 14 h to 16 h when temperatures peak, then resume activities later as the sun drops.

When you’re resting, the human body generates far less heat and uses less energy. The Mediterranean siesta lines up exactly with the time of day when outdoor temperatures hit their highest point. 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 other 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 matters too, for straightforward physical reasons. Light shades reflect sunlight, while dark colours absorb it and convert it into heat. Wearing a black T-shirt in 35 °C effectively turns you into a walking radiator.

The chilled-laundry trick can bring immediate relief. Put sheets, T-shirts and underwear in the fridge for thirty minutes before wearing or using them. That instant coolness against the skin temporarily offsets the surrounding heat and helps you cope with thermal 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 a minimal, practical setup. Duvets and blankets should be replaced with a simple linen or cotton sheet. These natural fibres wick away body moisture better than synthetics. In extreme cases, sleeping directly on the mattress avoids extra layers of fabric altogether.

A chilled pillow can work wonders for heat-related insomnia. One hour in the freezer before bed is enough to create a cool spot that lasts for several hours. This makes it possible to fall asleep even when night-time temperatures climb above 25 °C - and it doesn’t cost much.

A hot-water bottle in summer sounds absurd, doesn’t it? Yet a frozen hot-water bottle, filled with cold water and left in the freezer for two hours, releases coolness for hours in bed. Its gradual cooling helps you drift off without a thermal shock.

In summer, you must stay hydrated

Hydration in high heat follows counter-intuitive rules. Ice-cold drinks, despite the instant appeal, hydrate less effectively than lukewarm liquids. They can cause thermal shock that disrupts the body’s regulation. Fresh mint infusions and cucumber-flavoured water, drunk at room temperature, cool you more sustainably.

Frequency matters more than volume. Taking small sips very regularly improves absorption. Your body handles a steady intake of fluids better than a large amount all at once. This approach keeps hydration stable, even in extreme heat.

Food also helps actively cool the body. Watermelon, cucumber, tomato and courgette contain more than 90% water and perfectly complement what you drink. These water-rich foods cool you from the inside while also replenishing the minerals lost through sweating.

Invest smartly without breaking the bank

A few modest purchases can dramatically improve thermal comfort. A 35 euros electric mister combines airflow and water evaporation to create a natural air-conditioning effect. Provided you keep it nearby - since it won’t cool a large space - it delivers immediate relief.

A fan uses 50 watts compared with 2000 watts for a portable air conditioner. Over three months of heavy use, the electricity saving tops 200 euros. And for remote workers - or anyone stuck in an office where colleagues argue over the thermostat - the best move is a desk fan.

This personal fan keeps you cooler all day while using very little power. You now have every technique you need to stay cool for less.