Drowsiness, crashes, fires… what your car risks in case of overheating

France is going through another heat wave period, enough to be even more vigilant if you’re heading out or returning from holiday.

With a thermometer again exceeding 30°C this week, departures and returns from holidays for the coming weekend must be done with great care. Possibility of some good advice if you are going out.

Breakdown: tire, battery… check your car carefully!

Before a long drive, it’s always wise to take a quick tour of the vehicle, especially if you haven’t had a chance to have it serviced at a garage recently. And it is even more recommended during a heat wave.

Check as a minimum engine oil and coolant level (always cold engine) as well tire wear and pressure.

This tire check is crucial. Under-inflation increases the risk of explosion, especially on the highway with the friction generating extra heat.

The recommended pressure for your vehicle’s tires is indicated on the edge of the door, in the glove compartment or in your vehicle’s maintenance booklet. It is also advisable to drive slightly overinflated, between + 0.2 or 0.3 bar. Checking and inflation should be done cold, but if you need to do it hot, remember to add 0.3 bar to the recommended pressure when cold.

Do not forget to also check the pressure of the spare tire, if you have one, or the presence of an anti-puncture kit on board.

12V battery of your vehicle may also have difficulty withstanding the heat:

“A battery in a temperate zone will last 47 months versus 30 months in a very hot zone. During heat waves, the most frequent problems are essentially battery and engine cooling problems. The battery is much more stressed (air conditioning and ventilation then run at full speed, and the electrolyte tends to dry out),” recalls Ctek, a company that offers battery charging and maintenance solutions.

If your car has been immobilized for some time, before the big departure or at your resort, check that it is in good condition before D-Day to avoid this unpleasant surprise. The heat, but also the fact that it’s only short trips, that modern equipment continues to pump energy, or that a “hands-free” key remains close to the vehicle (and therefore continues to communicate with it) can help drain the battery during an extended shutdown. The cases were multiplied at the end of the imprisonments linked to covid-19, with a start which is no longer guaranteed for certain models after only 15 days without driving.

Drowsiness: multiply the breaks

With high temperatures, the risk of drowsiness is increased. We will then remind you of some common sense advice: a good night’s sleep before the big departure and not to specify an arrival time to limit stress.

Above all, when you’re on the road, don’t hesitate to stop as soon as you feel the first signs of fatigue, and don’t necessarily wait for the two-hour drive. Duration after which it is advisable to take a break, but should be taken as a maximum duration.

Drowsiness remains the most frequent cause of death on the motorway network, recently recalled the Vinci Autoroutes Foundation, forwarding a study carried out by Autoroutes Trafic, a historic player in traffic information in France, and Arcadis, a mobility and travel design office.

“In particular, the results reveal that 20% of long journeys are made without stopping and that 55% of stop times at rest stops are less than 20 minutes, which is insufficient time to take a restorative break,” a press release indicated.

Siesta awareness areas in areas of the Vinci network this summer 2022.
Siesta awareness areas in areas of the Vinci network this summer 2022. © Fondation Vinci Autoroutes

In July, at the Limours-Janvry rest stop (A10), the Vinci Autoroutes Foundation offered holidaymakers the opportunity to experience a short siesta in cocoons designed by its partner Nap&Up (pictured above), a start-up promoting the practice of micro-naps. To support these “nap drivers” and facilitate their relaxation, Nap&Up and the Foundation have jointly designed an exclusive podcast that allows them to easily fall asleep during a break.

An operation that is renewed until August 20, every Friday and Saturday, in 14 lively areas of the Vinci network.

Overheating on board, how to limit the risks?

Obvious danger during a heat wave: overheating on board. It is already possible to limit the increase in temperature when the vehicle is stationary by favoring places in the shade. But they are often taken by storm, so the ideal is still to have sunshades to the windscreen, but also to the side windows, which can thus remain less exposed while driving.

With an outside temperature of over 30°C, the temperature on board can reach 70°C, with a real risk of burns when touching surfaces on board, steering wheel, gear lever and seat, warns Assurland.

More than ever before, a few rules to follow make good use of your air conditioning system: ventilate the car well before leaving, with the doors wide open, and drive the first few kilometers with the windows open. When the temperature has dropped or when you arrive on the highways, you can close the windows and turn on the air conditioning.

We generally recommend not to have a difference greater than 5 to 7°C with the outside temperature. It is also better to avoid directing the air flow towards your face and that of the passengers. By pointing it towards the ceiling, the cold diffuses better and everyone can enjoy it.

With the multiplication of fires this summer throughout France, we must also remain vigilant on this point, reminds the insurance comparator:

“Theoretically, on a thermal vehicle in good condition, there is no risk of fire, fuel tanks and circuits (petrol or diesel) are safe. But for a vehicle with a fuel leak, the consequences high heat can be dramatic”, with “fuel vapors or a few drops which can ignite and cause a serious fire”.

Another risk, although it remains limited: park after a long drive in an area where tall grass may come into contact with hot parts of the vehicle. This was the suspected cause of a fire on the Belgian coast at the end of July.

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