This non-toxic and non-caustic gel pack can be used as a hot or cold compress. To warm, place pack in microwavable container, set the microwave at medium power, and heat pack at 30 second intervals until desired temperature is achieved. Or cover pack completely with 80 - 90癈 water and soak for 3 - 5 minutes. For cold compress, it should be placed in freezers for one hour before using.