Web MD -- Protecting your kids from the sun involves more than just slathering on whatever sunscreen's lying around.
FDA regulations meant to help consumers choose the right sunscreen have kicked in this year and may be causing some confusion. The "Sun Protection Factor," or SPF, reflects how much protection is offered against UV-B rays, the main cause of sunburn. But it's never meant anything about UV-A rays, which cause skin damage and aging. UV-A and UV-B both contribute to skin cancer. The new regulations still allow manufacturers to include an SPF against UV-B, but they can only label their products as "broad spectrum" if both UV-A and UV-B are blocked.
You'll also no longer see sunscreens claiming to be "waterproof" or "sweat proof" because, well, they never really are. Some might be labeled "water resistant," but like all sunscreens they'll recommend reapplication after two hours. No one has been able to make a sunscreen that lasts much longer than that.
It's also very important to use a full dose of sunscreen, which is about one full ounce for an adult. That's a shot-glass full, or two tablespoons—a whole lot. Most people use much less, which drastically reduces the effectiveness.
You can get good sun protection without relying on as much sunscreen. "Rashguard" shirts like surfers wear are impregnated with sunscreen, and even an ordinary T-shirt offers some protection. It's also best to avoid direct sun altogether when the sun is directly overhead—that's when rays are the most intense.
Don't forget about eyes. Long-term sun exposure contributes to damage to the eye as well, and kids need sunglasses just as much as adults.
Any sunburn—that is, redness in the skin after sun exposure—means that some sun damage has occurred. Repeated sunburns are bad news, and even a single blistering sunburn will increase the risk of cancer. While some sun exposure helps the body make enough Vitamin D, excessive sun exposure can really add up. Just how careful you need to be will depend on your child's skin type (fairer skin is more likely to be damaged by sun) and your family history (skin cancer does run in families, and sun damage increases the risk.) Smoking is another risk factor for skin cancer that parents may need to keep in mind for themselves. Sunburns, cancer, and aged wrinkly skin are summer's gifts that your family doesn't need.