But what's arguably more arduous than slathering lotion onto a screaming 3-year-old is choosing the right sunscreen.

Not only are we presented with hundreds of choices — cool mist or lotion, sensitive skin or extra sensitive skin, SPF 30 or 50 or 75 — many are apparently unsafe, too. Some critics warn that sunscreens can cause cancer while others claim that certain ingredients increase the risk of infertility. Dr. Oz says your sunscreen might be poisonous. In its 2013 Guide to Sunscreens, the nonprofit Environmental Working Group says that only 25 percent of sunscreens on the market are "free of ingredients with serious safety concerns.