Athletic Works Boy's Thermal Top & Bottom Set, Size XL (14-16) Color Gray 

You cannot go wrong with this Athletic Works Boy's Waffle Knit Thermal Set. This thermal set is extra warm yet breathable thanks to their cotton/poly blend construction. He'll keep warm in this base layer as ribbed wrist and ankle cuffs trap in precious body heat. Your big boy will feel comfortable and cozy in this fitted thermal set that features a crew neckline for a classic look that can also double as PJs