Heat on Friday nudged outdoor playtime earlier and cut it shorter than scheduled for nearly 70 children at Stockton's Seifert Community Center day camp.

Once it got going, though, campers cheered on teammates during a running, jumping, twirling relay race, while other groups played basketball or made up their own games on playground equipment. According to environmentalists, child-development specialists and other advocates, telling kids to "Go out and play" can keep them healthier, less stressed and more imaginative.

But, those advocates worry, what used to be something children just did - playing outside - is becoming increasingly rare amid the wide-ranging allure of television, video games and other indoor pursuits, as well as parents' worries about sending their kids out-of-doors without supervision.