You may have already known this but I didn't! I always keep my sunscreen in my pool bag and leave it in my car. Well, according to Real Simple mag this is a bad idea...making it less potent or completely ineffective!
Is it OK to store sunscreen or a lip balm with SPF in a glove compartment?
No, especially during summer. Once the car heats up in the sun, "high temperatures can cause the sunscreen’s active ingredients to degrade right in the container," says Badreshia-Bansal. And the lip balm will melt, to boot. "When you apply a degraded sunscreen or balm to your skin, you’re not getting the SPF that’s indicated on the bottle," she warns. "In fact, you might be applying nothing more than a thick moisturizer."