Articles comprising multilayer coextruded films having polyester and polyamide layers adhered with a copolymer of polyester and a sulfonic acid or its derivative, having high oxygen barrier properties and temperature resistance that are capable of being heated to 425° F. in a conventional oven are disclosed. The articles are packages, such as bags, pouches, and casings that are particularly useful for packaging and cooking foodstuffs such as meat, poultry, seafood and the like.