If you are spending a lot of time outside, you may want to apply sunscreen every time. That’s as one in five Americans develop some form of skin cancer by the time they’re 70.

Blue Cross Blue Shield of Michigan’s Dr. Crystal Lee says sunscreen protects your skin.

“The higher the number, the longer the protection, but ideally you still need to reapply sunscreen but ideally you still need to reapply sunscreen every two, two and a half hours,” Lee said.

Lee says everyone should get a skin exam every year by a dermatologist or their primary doctor. She also advises everyone to look for any changes in their skin.