Vehicles parked in direct sunlight can heat up quickly, turning everyday items into potential safety hazards.
From exploding fizzy drink cans to leaking pens and damaged dashboards, the cost of leaving the wrong item in your car can soon mount up.
To help drivers avoid unnecessary damage and expensive repair bills, Nationwide Vehicle Contracts has highlighted five common items that should never be left in a vehicle during a heatwave.
A can of fizzy drink might seem harmless, but leaving one in a hot car can quickly cause problems.
As temperatures rise, pressure builds inside carbonated drinks, causing cans and bottles to swell or even burst. If this happens, sticky residue can spread throughout the interior, requiring professional valeting that can cost between £50 and £150.
If a can bursts while you're driving, it could also become a dangerous distraction.
Pens are another everyday item that can cause expensive damage if left inside a hot car.
High temperatures can cause the ink to leak or the pen to burst, leaving permanent stains on seats, carpets and interior trim. In more severe cases, removing the damage could require professional cleaning or even replacing upholstery, with repair costs potentially exceeding £1,000.
Air fresheners can also be affected by extreme heat.
Oil-based air fresheners may leak or melt in extreme heat, leaving stubborn stains on dashboards, and interior plastics. In some cases, the chemicals can even damage or warp dashboard plastics, with repair costs ranging from £50 to £400.
To help prevent unnecessary damage, avoid leaving air fresheners in direct sunlight during hot weather.
It's not only the items you leave in your car that can become dangerous during a heatwave.
Metal seatbelt buckles, steering wheels and other interior surfaces can become extremely hot after a vehicle has been parked in direct sunlight.
Touching these surfaces immediately after getting into the car can cause minor burns, particularly for children and pets. Whenever possible, park in the shade and allow the cabin to cool before setting off to help reduce the risk.
Leaving sunglasses or prescription glasses on the dashboard may seem convenient, but it can pose a serious safety risk.
In direct sunlight, lenses can act like a magnifying glass, concentrating the sun's rays onto upholstery or dashboard surfaces. In extreme cases, this concentrated heat can scorch interior surfaces or even ignite nearby materials.
It's always best to store glasses safely in a case or take them with you when leaving the vehicle.
A few simple precautions can help protect both your vehicle and your belongings during periods of hot weather.
Where possible:
- Remove heat-sensitive items before leaving your car.
- Park in the shade or use a windscreen sunshade.
- Leave valuables out of direct sunlight.
- Allow the cabin to cool before driving away.
These small steps can help reduce the risk of damage and avoid unnecessary repair costs.
“What might seem like harmless everyday items can quickly become a safety risk or result in costly damage. Something as simple as a fizzy drink left on a seat or dashboard can expand and burst, leaving drivers with an expensive and time-consuming clean-up. In some cases, it can even damage electronics or upholstery.
Taking a few moments to remove items from your car or keep them out of direct sunlight can help avoid unnecessary injury and costs”
Hot weather can affect more than just your comfort behind the wheel. Taking a few minutes to remove everyday items from your vehicle and parking sensibly can help prevent avoidable damage, reduce repair bills and make summer driving safer.
For more seasonal driving advice and vehicle maintenance tips, explore the latest guides on the Nationwide Vehicle Contracts blog.
Originally posted: 16th July 2026