Use one of these creative solutions to make your own ice pack using common household ingredients.
Option 1 using Corn Syrup: Pour some corn syrup into a ziploc bag and place in the freezer. It will become gel-like and not freeze solid.
Option 2 using Dish Soap: Pour some dish soap into a ziploc bag and place in the freezer. After about 2 hours it will be a softer type of ice pack. If left in the freezer longer, it will become a harder ice pack.
Option 3 using Rubbing Alcohol: Pour 1½ cups water and ½ cup rubbing alcohol (I use 70% isopropyl alcohol) into a quart size ziploc bag and place in the freezer. You can make a smaller version by combing ¾ cup water and ¼ cup rubbing alcohol in a snack size ziploc bag.
Option 4 using Salt: Combine 2 cups water and 2 tablespoons salt (I use regular table salt) in a quart size ziploc bag and place in the freezer.
Option 5 using a Sponge: Get a sponge wet with water and squeeze it just a bit so it is not dripping. Place in the freezer until the sponge feels hard and solid.
For extra security you can double bag your ice packs too. Put the first ziploc bag, with the seal side facing downward, into a second ziploc bag and then place in the freezer.