For some parts of the United States, this has been a brutally hot summer. Temperature records have been set left and right. Do you know when to apply creamy sunscreen? Do you know the SPF number of the sunscreen? As you get pumped up to go the beach for relief, it’s easy to drop by a store and pick up the nearest bottle of sunscreen.

But you need to do your homework. has a great article on how to interpret SPF numbers. The issue is critical because too much sun can cause skin cancer. You do not want to be over-exposed to the sun’s ultraviolet (UV) rays.

Information from the American Academy of Dermatology explains these SPF numbers and how to re-apply sunscreen as you’re soaking in the rays during this toasty summer.

Don’t think you can escape potentially harmful UV rays if you live in a cooler part of the country. Sunshine, even through filtered clouds on a cool day, can affect the skin.

This article links to the American Cancer Society, where you can learn more about sun safety.