DIY Ice Pack Recipe
Select Ziploc bag size of choice (double or triple bag to protect against leaks).
Get a big bottle of cheap dish soap.
rubbing alcohol
Load up the Ziploc about 1/2 – 3/4 full. Close the bag a couple of times squishing out the air each time. Freeze.
Or here is another one
3 cups water
1 cup rubbing alcohol
Note: The more alcohol you use, the softer the pack will be, making it
more gentle on injuries than an ice pack.