A system for heating and dispensing foam-in-bag packaging bags comprises a housing that rotatably supports a roll of a continuous web of interconnected foam-in-bag packaging bags, and at least one heater for heating bags to an elevated temperature prior to the bags being dispensed from the housing. A heated bag is dispensed and is detached from the web, and is then manipulated to mix foam precursor chemicals contained in separate compartments in the bag to begin a foam-forming reaction in the bag.