If you thought you were being responsible by always keeping sunscreen at the ready in your car during the summer months, unfortunately, you have to think again.
The sunscreen you rely on to protect your skin can be rendered less effective by heat — and there’s no shortage of that in a car during the summer.
"When sunscreen is stored in a high temperature, the effectiveness decreases, and the sunscreen becomes less stable and reliable. When it gets hot or is stored above 77 degrees Fahrenheit, the potency is destroyed, and the sunscreen will degrade," cosmetic dermatologist Dr. Fredric S. Brandt, MD, told Refinery29.