As children head outdoors for summertime fun, warm rays and tanned skin can be a warning of future health risks.

Between 60% and 80% of a person's sun exposure occurs before age 18, and skin damage occurring during adolescence is a key factor in the development of skin cancer, according to the American Academy of Pediatrics. A combination of clothing, sun avoidance and sunscreen should be part of your child's sun protection, said pediatrician and skin care authority Dan Krowchuck, M.D.,FAAP.

Dress your child in fabrics with a tight weave, such as natural cotton or Lycra. Sunglasses should block at least 99% of both ultraviolet A (UVA) and ultraviolet B (UVB) rays, while hats should have a 3-inch bill and be turned forward.

Although the afternoon is a tempting time for a swim, UV radiation is strongest between 10 a.m. and 4 p.m., and children should avoid outdoor activities during this time. A shady spot can offer temporary relief from the sun.

Children should use sunscreen when they are outside. Here are some tips to make sure your child's sunscreen is effective:

  • Choose a sunscreen labeled “broad-spectrum” to screen out both UVA and UVB rays.

  • Choose a sunscreen with a sun protection factor (SPF) of 15 or higher. Because many people do not apply enough, choosing an SPF 30 can provide a margin of error, Dr. Krowchuk said.

  • Sunscreens should be water-resistant or waterproof.

  • About 1 ounce of sunscreen (the size of a golf ball) should cover a young adult from head to toe. Apply sunscreen at least 30 minutes before going out in the sun to allow time to dry. Make sure to rub it in well.

  • If sunscreen irritates your child's face, try using a sunscreen stick.

  • Reapply sunscreen every two hours or after swimming or sweating.

  • Follow the expiration date on the bottle. If your sunscreen does not have an expiration date, call the company or purchase a new bottle each year.

Extra precautions should be followed for babies younger than 6 months: keep babies out of direct sunlight; dress them in lightweight long pants,long-sleeved shirts, brimmed hats and sunglasses; and apply a small amount of sunscreen to small areas of the body, such as the face and the backs of hands,if clothing and shade are not available.