... :Whether used HOT or COLD, it is advisable to check that thetemperature is not too extreme against the skin. ... and immerse the gel pack for approximately 4-10minutes(check after 4 minutes to see if the desired temperature ... if it hasn't, return to the water and check again after a minute, Repeat until the correct temperature has ... glycol, CMC, Water bear shape hot cold pack, nylon with PVC material