Before you head outdoors to enjoy summer activities, slather on the sunscreen. The average adult requires 1 ounce of sunscreen - 2 tablespoons’ worth - for full body coverage. Apply 15 to 30 minutes before sun exposure and reapply every one to two hours while outdoors.

The July issue of Mayo Clinic Women’s HealthSource offers tips to select the right sunscreen. Look for one that offers:

Broad-spectrum protection. Find one that protects against ultraviolet A (UVA) and ultraviolet B (UVB) sun rays. Both can damage the skin.

SPF of 15 or higher. A sun protection factor (SPF) of 15 deflects about 93 percent of the UVB rays and allows you to remain in the sun 15 times longer than you normally would before getting burned. Higher SPFs deflect about 97 percent of the UVB rays.

Water-resistant or waterproof qualities. This is especially important if you’ll be swimming or perspiring heavily. Water-resistant sunscreen protects for 40 minutes; waterproof sunscreen for up to 80 minutes.

Skin-appropriate form. If your skin is dry, choose a cream or lotion sunscreen to increase moisture. For oily skin, choose an oil-free sunscreen. If you have sensitive skin, look for a sunscreen that contains only zinc oxide or titanium dioxide. These ingredients provide a physical barrier against UV rays rather than chemically absorbing them, which may be gentler on your skin. Avoid alcohol-based sunscreen if you have rosacea or eczema.