Sam Berns, 15, who has the very rare premature-aging disease progeria, plays the drums in his high school's marching band. Courtesy of the Progeria Research Foundation hide caption

itoggle caption Courtesy of the Progeria Research Foundation

Eric Wiltz cavorts on a trampoline in New Orleans in 2010. Everything is fun and games on the backyard attractions until someone gets hurt, a leading group of pediatricians says. Sean Gardner/Getty Images hide caption

itoggle caption Sean Gardner/Getty Images

The Durban Children's hospital opened in 1931, as a facility for all races, but tensions during the apartheid era forced it to close in the 1980s. Courtesy of KwaZulu-Natal Children's Hospital hide caption

itoggle caption Courtesy of KwaZulu-Natal Children's Hospital

Evan Ciangiulli, 4, completes a warmup that teaches him the right way to lift weights. Karen Castillo Farfan/NPR hide caption

itoggle caption Karen Castillo Farfan/NPR

Canned food is a source of BPA exposure, but researchers aren't sure whether it causes childhood obesity. Above, the soup isle at a grocery store in Washington, D.C. Maggie Starbard/NPR hide caption

itoggle caption Maggie Starbard/NPR

A label warns parents to keep Tide laundry detergent packets away from small children. Pat Sullivan/AP hide caption

itoggle caption Pat Sullivan/AP

People wait in line at the Durham County Health Department for the H1N1 flu vaccination in Durham, N.C., in November 2009. Gerry Broome/AP hide caption

itoggle caption Gerry Broome/AP

Though scientists have identified sleepwalking triggers, the condition is still a bit of a mystery. Victoria Alexandrova/iStockphoto.com hide caption

itoggle caption Victoria Alexandrova/iStockphoto.com