Techni Ice HDR 4 Ply Reusable Ice & Heat Packs 20 Sheet Special Techni Ice is a high-tech multi-purpose product that can be used as either a sheet of ice or a heat pack. To heat the already hydrated Techni Ice, non-frozen, microwave one full sheet for 1 minute and then check to see if it's hot enough. If not, we recommend heating for another 30 second increments. Techni Ice can also be heated and used as a heat pack for sore muscles, Packs can be cut to any size -Re-usable, washable,non-toxic, sheet size 11"x15"