Our insulated reusable grocery bags keep foods (or medications, etc.) hot or cold for up to 3 hours! They are Reusable, Washable, Recyclable and work great keeping ice cream, frozen foods and beverages cold! Made in USA. These insulated reusable grocery bags can be used as a stand-alone bag, or you can easily fit them inside our TuckerBags designer grocery bags as an insulating liner. All our bags use the same patented 3-layer technology, which is an award winning, high -performance insulant. The association of an IR (ndlr: Infra Red) reflective material, a thick PE foam and an inner FDA approved, food-grade protective layer provides long lasting thermal protection for any temperature sensitive product, ranging from foods and drinks to drugs. Note that the bag itself does not produce heat or cold by itself. It simply insulates its content by isolating them from the outside environment and reducing any heat transfer. Outer Reflective Layer:: The dual layer acts as a reflector to outer heat, sunshine and moisture. It also helps the insulation layer retain the inner cold or hot inside the bag. Insulation core layer:: Millions of sealed capsules form a solid thermal insulation barrier. The thick foam preserves the cold by maintaining a constant, lower temperature. Inner Protective Layer:: Made of food grade materials. It forms the double lining. The inner layer is completely sealed to maximize thermal efficiency and keep in freshness. Holds up to 35lbs and made in USA.