Because of the special feature of the gel in the packaging.
It does not freeze in the freezer and it protects its coldness for a long period of time when it is taken out.
It maintains its temperature for a long period of time when it is heated with microwave or boiling water.
It is used in wrist twists, migraine and in places where cold compress is required in cold form, and in the joint pains and in places where hot compress is required in hot form.