Dynarex Instant Cold Pack with Urea (Non-Toxic) (4517) These one-time use disposable cold packs are instantly activated with a single squeeze. The non-toxic urea is used to make the solution cold within the portable ice pack. It is safe for use and is not harmful. Keep a few ice compresses in first aid kits sports aid kits and where ever you store medical supplies for emergencies. These instantly activated icepacks can be stored at room temperature and replace the need for fresh ice. Every individual single use instant cold pack is clearly marked with two arrows on the package indicating where to place one’s hand and squeeze to activate. The soft pack is flexible and conforms to the shape of the body where it is placed. They are ideal for relief of minor injuries or sprains and reduces swelling. Also great for pain relief from toothache headache bug bite or bee sting. Use whenever instant cold therapy is required. Ideal for relief of minor injuries or sprains and reduces swelling. Also great for pain relief from toothache headache bug bite or bee sting. Use whenever instant cold therapy is required. Dynarex provides Best in Class alternative to other leading brands. Includes: 1 Box of 24 Dynarex Instant Cold Packs with Urea (Non-Toxic) 4 x 5 Available as: 4511 Cold Pack 4” x 5” 4512 Cold Pack 5” x 9” 4516 Hot Pack 5” x 9” 4515 Perineal Instant Cold Pack with Self-Adhesive Strip 4 ½” x 12” 4517 Cold Pack with Urea (Non-Toxic) 4” x 5” 4518 Cold Pack with Urea (Non-Toxic) 5” x 9” Dynarex is your one-stop medical products brand since 1967.