Slather your kids with sunscreen now and they'll thank you later. "Physical blocks, like titanium dioxide and zinc oxide, are preferable to chemical sunblocks for young children because they aren't absorbed into the skin, where they can cause allergic reactions," says dermatologist Laurie J. Polis, director of SoHo Skin and Laser Dermatology, in New York City.

Dermatologists' picks: Sun Smart Maximum Protection SPF 30 Facial Sun Stick for Kids ($5.50, www.atforyou.com) and Neutrogena Sensitive Skin SPF 30 ($9 at drugstores). However, doctors caution against using any sunscreen on infants younger than six months. "Babies' skin is extremely susceptible to irritants. Clothing, hats, and umbrellas are the best way to protect them," says Polis.