Cool Tips for Hot Days – How to Keep Your Car Cool

Summer means travel – and often, heat. Especially in the car, warm days can quickly become uncomfortable. But with a few simple tricks, you can beat the summer heat: from smart parking to handy tools to small daily routines that help keep your car noticeably cooler.

In this blog post, we’ll show you the best tips for keeping your car at a comfortable temperature during hot weather – for better comfort, improved focus while driving, and a more relaxed journey. And as a bonus, you’ll also protect your car from potential heat damage.

How can you best protect yourself and your car from the heat?

The most important thing to protect both you and your car from extreme heat is to avoid direct sunlight and keep the interior as cool as possible. Park your car in the shade or a garage whenever you can. If that’s not an option, a reflective sunshade behind the windshield can significantly reduce heat buildup. Slightly opening a window (important: only if the area is secure!) can also help prevent a heat trap inside the car.

Here’s an interesting and effective trick from mathematician Professor Hannah Fry: To get hot air out of the car quickly, first fully open the rear window on the passenger side. Then, open and close the front door on the opposite side (driver’s side) several times. This creates an airflow that literally “pumps” the hot air out. It can noticeably reduce the interior temperature – without even turning on the air conditioning.

And if you don’t have time for tricks like that: electric cars can often be pre-cooled via app. That means you step into a pleasantly cool car even on hot summer days – without starting the engine. You’ll find electric cars with this feature at Carvolution, too – as part of a flexible, hassle-free car subscription, perfect for the summer.

What’s better when driving – air conditioning or windows down? This question sparks debate every summer. The fact is: at higher speeds – around 80 km/h or more – the air conditioning is more efficient, because open windows increase air resistance, which also increases energy consumption. In the city or at low speeds, opening the windows briefly to let in fresh air can be useful – especially if the air conditioning hasn't fully kicked in yet. The best approach: combine both wisely, depending on the situation.

Why is an overheated car a real safety risk?

The interior of a car can reach over 50°C (122°F) in a short time. For children, the elderly, and pets, this can be life-threatening, as they can’t regulate body temperature well. But even healthy adults are at risk: circulatory problems, dizziness, or loss of concentration can occur.

Heat also affects road safety – for example, if the driver’s reaction time is reduced due to the heat.

What damage can extreme heat cause?

Extreme heat can harm your car in many ways – both inside and on technical components. The interior is particularly vulnerable if the car is exposed to direct sunlight for several hours, especially at outside temperatures of 25–30°C (77–86°F) and above. After just 30 minutes, the temperature inside can climb over 40°C (104°F). When it’s 30–35°C (86–95°F) outside, even 50°C (122°F) inside is common – especially with closed windows and no sun protection. After one hour in the sun, interior temps can rise beyond 60°C (140°F).

Plastic parts like the dashboard or steering wheel can warp or crack over time due to the heat – especially with repeated exposure. Seats and panels may fade, and materials or adhesives may come loose, causing unpleasant odors.

But the impact isn’t just cosmetic – there are technical consequences too. The cooling system is heavily stressed on hot days, which can, in the worst case, lead to engine overheating. Electronic components such as sensors, control units, or displays are sensitive to high temperatures – especially when the interior remains above 50°C for long periods.

Another point: tire pressure rises with increasing outside temperature. On very hot days – over 30°C (86°F) – and long drives on hot asphalt, the pressure can increase so much that, in extreme cases, a tire blowout may occur. Car batteries also suffer under prolonged heat and may lose performance over time – especially when the car is parked unprotected in the sun for days.

And last but not least: certain items should never be left in a hot car. Spray cans, lighters, power banks, or glass bottles can heat up to dangerous levels at interior temperatures above 50–60°C (122–140°F). Explosions are rare, but fires or damage from leaking batteries can happen with strong and prolonged heat exposure.