little family trick: filling the freezer with ziploc bags of water is a quick way to make ice packs that you can add to the fridge to help keep it cold after power loss

If you are evacuating - freeze a glass of water, and put a penny on top of the ice. Check it when you return. If the penny is on top of ice - your food is good to go. If the penny is on the bottom (thawed, refrozen) - toss it. If the penny is in the middle (partial thaw) proceed w/caution

And clean plastic bottles (soda, ketchup, previously food use), and food storage containers.

also uh, good as general ice packs to use if you need an ice pack >.>