I have some clickable heat packs made by a company called Body Comfort. They have two states: a liquid state, when they can be clicked for heat; and a solid state, after they have been used, and need to be boiled in order to be returned to the liquid state.
They can only be frozen when in one of these states. Otherwise, the pack may burst.
According to Body Comfort Customer Service:
To use the heat packs as a cold pack you would not activate the heat pack by flexing the disk prior to placing it in the refrigerator or freezer.
You can use the heat packs as a cold pack by placing in refrigerator for 20 to 30 minutes and place on the desired body location. For faster results, store your Body Comfort click and heat packs in the refrigerator for instant use as a cold pack or click and generate instant heat. For colder desire, place in freezer. You will need to boil to regenerate pack after it has been frozen in order to use it as a heat pack.
So I’m going to put my pack into the freezer while it’s still in liquid form, and it has not yet been activated. I hope it works!