Freez Pak™ The Alaskan Reusable Ice Substitute. Just freeze and use over and over. Colder than ice. Long lasting. Safe, non-toxic. Leak proof bag. Helpful hints: Pre-cooled food will stay colder longer with Freez Pak™. Stacked Freez Paks™ keep food cold the longest. A small chest, fully packed, will stay cooler longer than a larger, partially loaded chest. www.lifoam.com.