With up to 6 hours of cooling, they're made to handle the heat! A Mini Ice Pack comes included as standard in all our Mini Lunch Bags. These new Ice Packs are made with a wipe-clean nylon outer material. The outstanding quality remains with the same gel contents inside, but these new ice packs have a stronger, condensation-free outer layer. The ice packs remain independently certified “food safe” and still comes with our machine washable cover.