Crafted in plush fleece with a fabric top, this 2-piece pajama set is extra cozy, but is it chemically treated- no way. Carter's cotton pajamas and separates are not flame resistant, but don't worry, they're designed with a snug and stretchy fit for safety and comfort, Carter's Little Boys Motorcycle Fleece Pajama, 2 Piece Set, Kids, Kids' Clothing - Pajamas