Polar Tech Re-Freez-R-Brix foam refrigerant pack. Re-Freez-R-Brix is a block of rigid foam that holds its shape frozen or thawed and is reusable. The Refrigerator in a bag. These refrigerants are non-toxic, sealed in a heavy plastic pouch, and are rated the best in foam refrigerants. Prevent thawing, keeps frozen products chilled for an extended period of time. Protects against freezing, when packaged in properly insulated containers, warmed Re-Freez-R-Brix release heat, keeping perishables from freezing. Protect from warming, keeps perishables requiring a temperature range of 32 to 60 degree F at a safe, uniform cool temperature for over 14 days.