12 Common Beauty Questions, Answered
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."