MIL just bought all 3 kids some polyester blanket sleepers at Sears. We keep our house very cold at night in the winter to save on heating bills, so we're planning to layer with cotton underneath to keep everyone toasty. The brand name is Planetzzz. It doesn't say anything on the package about then NOT being chemically treated. The package reads "this fabric is made of flame resistant fabric." Does this mean inherently flame resistant? There is no phone # on the package to call the company, no website either. I guess I could call Sears and somehow track down a number, but I'm hoping to avoid the hassle. If I'm not completely sure they're chemical-free, I'll return them.