1 | Choose the right sunscreen.

Look for a broad-spectrum sunscreen, which will block both UVA and UVB rays, with an SPF of at least 30. “The higher the number, the better,” says Jeannette Graf, MD, assistant clinical professor of dermatology at the Mount Sinai School of Medicine. “If someone’s going to be outdoors for a long time, I recommend they go with at least SPF 50.”

2 | Maximize coverage.

The point of sunscreen is to cover your entire body—not just the parts you can easily reach. According to Graf, the average adult needs to apply at least a shot glass of sunscreen for full protection. Kids generally require half that amount. Some often-overlooked areas: the tops of the ears, the bottoms of the feet, under the arms, between toes (wash away lotion and dry thoroughly after you’re out of the sun), on the scalp where the hair parts, and over the scalp for those with thinning hair (consider spray sunscreen for easy application).

3 | Reapply often.

Reapply sunscreen every two hours and any time that you emerge from water.

4 | Shade your eyes.

Harmful UV rays can damage your eyesight, so wearing sunglasses is a must, especially if you have retinopathy or cataracts. Look for labels that say the lenses protect against 99 to 100 percent of UVA and UVB rays.

5 | Tend to wounds.

If you have foot ulcers or other wounds on your skin, don’t cover them with sunscreen. Instead, ensure the wounds are clean and cover them with a bandage. In addition to blocking harmful rays, the bandage will keep bacteria from entering the wound.