At a glance
Heatwaves are hitting our country more and more often, and even more so in southern countries. Driving for long hours in temperatures above 30°C or even 40°C puts a strain on both your vehicle and its driver and passengers.
Here's a list to help you prepare and cope on the road during extreme heat, since a large number of assistance cases are opened every year because of the effects of heatwaves!
Before you leave
Time, day of departure and route
Favor a departure and route during the coolest hours of the day. Take into account the traffic density calendar and black spots on roads where you risk being slowed down at the time you'll be passing through. Also plan a route with frequent stops, preferably at places where you can relax and get something to drink.
The tires
It's often overlooked, but tires are of vital importance. They're what will get you safely to your destination! Check your tires before you leave and replace them as soon as they show too much wear or cracks. Keep in mind that a tire tends to lose pressure in hot weather, and an underinflated tire will handle worse, wear out faster and make you use more fuel. The risk of a blowout is therefore much higher if you drive on worn tires over scorching pavement. Also check that you have a spare wheel and its condition.
Read more in the articles "Underinflated or overinflated tires: what are the risks?" and "Do you have a spare wheel?"
The battery
The battery is put under heavy strain when it's cold (starting and heating the vehicle), but even more so when it's hot, especially for the cooling and air conditioning systems. Check the condition of your battery before you leave and don't overload it (by using electronic equipment, videos, etc.) while driving in a heatwave.
The oil level
An oil change before you leave will let you top up with "fresh" oil that has all its lubrication qualities intact.
The air conditioning
It's clear that your "AC" needs to work properly if you want to avoid your vehicle turning into an oven. Have it checked by a professional before you leave.
The coolant
This is also essential to your vehicle running properly. Check, or have checked, the level and quality of the coolant before you leave, and know how to avoid your engine overheating (read the article "How to avoid your car overheating" on this topic).
The windshield wipers
You'll likely need them to clean your windows, which get dirty from dust, insects (or bird droppings). Windshield wiper rubber can quickly deteriorate under the effect of heat. Also make sure to regularly top up your windshield washer fluid.
The bodywork
You can coat your vehicle's bodywork before you leave with a wax that will protect it from the sun's rays. Washing your car on arrival after a long trip will help thoroughly clean the bodywork and remove ingrained dust.
And for your passengers...
Don't forget refreshing drinks (in a cool box?) and perhaps a light snack in case you get stuck in traffic jams.
One last tip for the driver: set off well rested and relaxed!
During your trip
Passengers
Drink a refreshing beverage regularly (coffee won't stop you from dozing off if you're tired), and avoid any alcohol consumption. Keep a (cool) drink available on board, especially if you're transporting young children.
Remember to protect yourself (sunscreen, light clothing, a sun hat for young children).
The driver
Don't drive while tired. Driving for long periods can cause you to fall asleep at the wheel (read our tips here on how to fight it). Adopt a relaxed driving attitude, even in traffic jams. As the saying goes: it's better to arrive a little late than not to arrive at all!
Tempted to drive barefoot because of the heat? Careful, this is neither advisable nor really allowed (read "Driving in flip-flops or barefoot" on this topic).
The temperature inside the car
Try to keep a pleasant temperature inside the cabin, but not too cold. For the body, sudden temperature differences of more than 10°C (when you leave a vehicle that's "too cool" for you to step into a very hot ambient temperature) can cause headaches, fatigue or a chill. On top of that, this temperature gap will put too much strain on your AC's energy use. Keeping the interior temperature at a minimum of 25°C can be a good solution.
Open all the windows for the first few kilometers to cool down the inside of the vehicle before switching on your AC.
Stops
Plan regular stops (at least every 2 hours), try to park your vehicle in a shaded spot (taking into account how the sun moves), use sun visors (especially to protect your dashboard, which can quickly become scorching hot).
(A historical anecdote: did you know it was Napoleon Bonaparte who gave the order to plant trees along major roads, in order to protect his troops from the sun (or the rain)?)
Above all, never leave a (young) child or an animal alone and unsupervised in a vehicle. Remember that even with a window slightly open, a vehicle in full sun quickly turns into an oven.
Also read
- 12 questions to ask yourself before getting behind the wheel
- How can you use less fuel?
- Sunstroke and heatstroke: a few tips
First published: 06/2019 - Updated: 07/2025
