The quick-cooling ice pack refrigerates immediately, and can no longer be refrigerated after one use. Most of the fillings contained in it are ammonium salts such as ammonium sulfate, which are dissolved in water to absorb heat for cooling. This kind of ice pack is generally used in sports venues or outdoor sports venues. Can be used for cold compresses, emergency wound treatment and other unexpected situations. Helps control and relieve bruising and pain caused by minor sprains, bruises, strains, burns, etc., and quickly eliminate pain and discomfort caused by fever, headache, toothache, mosquito bites, etc.