(NEXSTAR) – Sunscreen is an important part of having fun in the sun, but should you really be keeping it in your car?

It’s no secret that the inside of your vehicle can become very hot during the summer months. During the first 30 minutes of sitting in the sun, the temperature within your car can rise by more than one degree a minute, Shelia Dunn, communications director with the National Motorists Association, tells Nexstar.

“So if it’s 90 degrees when you go into the store, within a half-hour, the inside of your car could be around 120 [degrees].”

And, of course, if your car is getting hotter, so are the items inside. According to Dunn, that could chemically impact your sunscreen. Sunscreens with active ingredients like oxybenzone and avobenzone can be degraded while sitting in a hot car, dermatologist Joseph Chao with Sutter Pacific Medical Foundation explains.

Sunscreen should be kept out of direct sun, the Food and Drug Administration advises. Instead, it should be wrapped in towels or kept in the shade or coolers. Even a popular brand of sunscreen, Banana Boat, includes a note on its FAQ page that while its products are tested “at elevated temperatures and sun light,” it is “best to store products at room temperature.”

Aerosol sunscreen isn’t any safer, either. Products under pressure, like aerosol cans, shouldn’t be stored in your car, Ellen Edmonds, Director of Communications with AAA tells Nexstar. Pressurized items typically have a temperature range in which they should be stored. Outside of that range, the items can explode.

To keep your vehicle cooler, Dunn recommends parking in shady spaces – under a tree, in a garage, on the shady side of a building – or using a windshield shade. Still, Dunn says parking in the shade “does not mean your car is immune to the heat.”

“A good rule of thumb—If you don’t want it to melt, don’t leave it in your car.”