Ergodyne Chill-Its 6230 Cooling Ice Vest, Large/X-Large LONG LASTING COOLING maintains a constant 64F/18C for up to 4 hours INCLUDES 2 ICE PACKS Wear both or one to rotate with the other EASY ACTIVATION place packs in a cooler, freezer, or refrigerator for 15-20 minutes DURABLE AND REUSABLE Product can be re-used over and over again. Just freeze, refrigerate, or soak in ice water to re-activate MACHINE WASHABLE