YES, foam insulation or general insulation works by trapping the heat of hot items within the cooler via the interior insulating walls. You can fill up plastic bags with hot water for extra heat and then place your cargo over them. Please do this only with a hard-sided cooler because it has better thermal insulation capabilities than a soft cooler like a backpack cooler. This is to avoid accidentally scalding yourself and damaging the soft coolers' fabric lining while carrying the heated cargo by accident.