How To Keep Your Car Cool In Summer

Why does your car heat up quickly? 

Your car heats up rapidly due to a process called the greenhouse effect. Sunlight passes through windows, heating seats, dashboards, and other interior surfaces. These heated surfaces radiate infrared energy, trapping heat inside car interiors and causing temperatures to spike quickly. 

In fact, on a hot day, the temperature inside a car can increase by over 50% in just one hour, and understanding the effect helps you take effective steps to keep your car cool.

Practical ways to keep your car cool

Park in the shade when possible 

Strategically parking your vehicle in shaded areas, such as underneath trees or in underground car parks, significantly reduces how much the internal temperature will rise. If shade isn't available, position your car so the sun hits the rear window instead of the dashboard. 

Use sun shades and window covers 

Reflective sun shades are essential for a cool car. They work by reflecting sunlight away from your car interior, drastically reducing how hot it gets. 

Car sun shades are affordable, readily available, and particularly beneficial for windshields and rear windows. If you’re travelling with children or pets, they’re great at protecting your passengers from direct sun exposure.

Protect your seats and steering wheel 

Dark interiors absorb more heat and can become dangerously hot to touch, making it uncomfortable for you, the driver, and your passengers. 

When you’re not driving, protect your seats and steering wheel by covering them with light-coloured towels or seat covers to stop them from getting too hot. 

Consider tinting your windows 

Window tinting reduces how much sunlight can pass through your windows and will protect your car's interior from harmful UV rays. 

Professionally installed window tints can lower internal temperatures, increase privacy, and protect upholstery. 

If you choose to tint your windows, the front windscreen must allow at least 75% of light through, and the front side windows must allow at least 70%, otherwise you risk a £60 Fixed Penalty Notice (FPN) and 3 penalty points on your license.

How to use car air conditioning effectively

Knowing how to use car air conditioning properly is important, and knowing when to use air recirculation can help you cool your car down significantly.

Maximise your air conditioning efficiency 

If you find that your car is too hot, try opening your windows slightly when you start driving to quickly release trapped hot air. 

After a minute, close them and switch to internal air recirculation mode to keep the cool air moving around the cabin, and gradually adjust the temperature to avoid strain on your AC system.

Recognise when your car air conditioning needs servicing 

Regular air conditioning checks help to ensure your system remains effective. 

If you find your car air con blowing hot air, or notice unusual smells or noises, these are signs your AC may need servicing. As such, it’s important to schedule regular checks every two years for optimal performance.

How to cool a car down quickly

When faced with an overheated interior, these detailed steps will help you cool your car quickly and efficiently:

• Open the front passenger window fully, then repeatedly open and close the driver's door to quickly expel hot air. Doing this helps to draw out trapped heat and cool your car’s interior.
• Turn your climate control or air conditioning to its coldest setting for a few minutes, then gradually adjust to maintain a comfortable level of cooling.
• Drive with windows slightly open for a few minutes to increase air circulation before fully closing them once the AC has cooled the air to a comfortable temperature.
• Consider using portable car coolers or fans as an additional cooling method on hotter days.

Common mistakes to avoid during a heatwave

Don't leave windows open unattended 

Leaving windows slightly open to ventilate parked cars may seem harmless, but it can invalidate your insurance and make your vehicle vulnerable to theft. Insurance companies classify this as negligence, which could lead to them rejecting theft or vandalism claims. Instead, you should use window shades and park strategically to keep your car at a comfortable temperature.

Never leave pets or children inside a hot car 

Interior car temperatures rise dangerously quickly, becoming life-threatening within minutes. On a 22°C day, interior temperatures can reach 47°C in just one hour. Leaving pets or children unattended carries severe risks and legal penalties under the Animal Welfare Act 2006 and child neglect laws.

Avoid keeping dangerous items inside your car 

Many everyday items can become hazardous when left inside hot cars, from electronics to bottled drinks. Read our guide on what not to leave in your car during a heatwave for detailed advice.

Heatwave advice for electric vehicles 

While a lot of the advice above applies to electric vehicles (EVs), they require additional specific care during high temperatures to protect their batteries and maintain performance:

• High temperatures can negatively impact EV battery efficiency and lifespan, to avoid this, try to park in shaded areas or covered spaces to protect the battery.
• After long journeys in hot weather, allow your battery to cool before plugging it in to charge. Immediate charging can add thermal stress and could potentially reduce battery longevity.
• If available, use scheduled pre-conditioning to cool the cabin before you get in. Cooling your car while plugged in can optimise battery life, giving you a comfortable interior temperature without draining power during your drive.
• Monitor battery temperature indicators closely, as managing battery heat effectively during heatwaves can prolong your EV's overall battery health and efficiency.

Heatwave preparation checklist for your car 

Prepare ahead of summer heatwaves by regularly checking:

• Coolant levels, topping up as necessary to prevent engine overheating.
• Tyre pressure, as heat expands tyres and incorrect pressure can impact performance and safety.
• Battery condition, as extreme heat can reduce battery longevity and efficiency.
• Air conditioning system, to ensure reliable cooling performance during extreme heat.

By following these straightforward steps, you can ensure your summer driving remains safe, comfortable, and stress-free. For further advice or servicing ahead of hot weather, the Dick Lovett team is always here to help. Get in touch today.