Heat retaining hood assemblies include a plenum with an interior side and an exterior side, wherein the plenum restricts heat from flowing from the interior side to the exterior side, and an exhaust duct fluidly connected to the exterior side of the plenum, wherein the plenum includes one or more contours to direct the exhaust on the interior side to an intake opening of the exhaust duct, and wherein the exhaust flows from the intake opening to a release vent of the exhaust duct disposed on the exterior side of the plenum.