You have a six year old child with you in your car. You have just parked so you can collect a prescription from the chemist. You should:
How fast can a car heat up in the sun?
Parked cars can get dangerously hot even on cool days, but let's look at a few temperatures and see how long it takes for the interior of the car to heat up.
If the outside temperature is 24C (75F) then it will reach 38C (100F) in ten minutes and 49C (120F) in 30 minutes. While 24C is a pleasant day, what about one of our hotter days?
If the outside temperature is 29C (85F) then within around 7 minutes it will be up to 38C (100F) and 49C (120F) within 30 minutes.
Sometimes we get really hot days, like 38C (100F) outside. In 15 minutes the interior of your car will be 60C (140F).
Never leave children or animals unattended in a car as they can easily lock themselves in the vehicle. Also, you don't know whether you'll become distracted or unable to return to the car. Extreme heat for children or animals can cause brain damage. Once the child's body temperature hits 41.5C (107F) enzymes are destroyed in the cells.
Leaving the windows open a crack makes very little difference as airflow through the car is insignificant. There is more information about vehicle heating here.
How to reduce the amount your car heats up in summer
To help reduce the amount your car heats up in the sun you can try the following:
- Leave the windows down as much as is safe while maintaining vehicle security (this doesn't have much effect but is better than nothing)
- Use a reflective screen on the windshield, as shown above
- Park in the shade
- Use a solar-powered fan to keep the air moving
- Close the sunroof blind so it's almost shut, but leave the sunroof open a little
- Use shades on the side windows
- Buy a lighter coloured car which reflects heat more effectively
- Get your windows tinted (but be careful to stay within the law).
When the temperature in the car heats up too much it can make it difficult for you to hold the steering wheel, and black leather seats can burn skin. Excessive heat can increase the level of volatile organic compounds released by plastics in the car interior, too.