A: Trish, it's good that you're thinking about protecting your children from the sun. Although playing in the pool in the summer is very fun and healthy for your children, their exposure to the sun's ultraviolet rays puts them at risk for sunburn, aging of the skin, and skin cancer. It's estimated that 80% of our lifetime exposure to the sun's damaging rays occurs during childhood, so it is important to protect your children as best as possible.

As you noted, sunscreen is one way to protect your children from the sun. SPF stands for Sun Protection Factor—the sunscreen's SPF number represents a multiplier for the increase in the amount of time it would take to get a sunburn compared to bare skin without sunscreen. For example, using sunscreen with an SPF of 15, it would take 15 times as long to get a sunburn. If it normally takes 10 minutes to get a sunburn, sunscreen with an SPF 15 should protect your child for 150 minutes, or 2½ hours. Of course, the actual length of protection depends on how strong the sun is on a given day, how thick a coating of sunscreen your children have applied, and whether the sunscreen has been washed off by swimming or sweating.

The American Academy of Pediatrics recommends the following guidelines for sunscreen for children:

• Use a sunscreen of at least SPF 15 to filter out over 90% of the sun's ultraviolet rays. While SPF 15 filters out 92% of the rays, SPF 30 provides only a slight improvement filtering out 97% of the rays, and SPF 45 only slightly more.
• Choose a sunscreen that filters out both UVA and UVB rays; and a waterproof sunscreen if your children are playing in the water.
• Apply sunscreen 20-30 minutes before going outdoors. Apply sunscreen to all exposed skin, especially the face, ears, neck, shoulders, and arms which are most exposed to the sun. Don't put sunscreen on your children's eyelids, since it can sting if it gets in their eyes.
• Reapply sunscreen at least every 2 hours and after swimming
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  Remember that sunscreen is only one line of protection. Be sure to take these other steps as well:
  
  
• Try to avoid outdoor play at mid-day (10 a.m. to 4 p.m.) when the sun's rays are strongest.
• Play in the shade as much as possible. This is especially important for babies under 6 months of age.
• Dress your children in light-colored, loose-fitting clothes that cover as much skin as possible.
• Have your children wear a hat with a brim that shades their face, and preferably flaps that shade the neck. Sunglasses with UV protection can also help protect your children's eyes.