If you have ever gone away from home for a week or more only to come back set some meat out to thaw only to find that it had spoiled while you were gone due to a power failure you may want to try this simple little trick.
Get a small container it can be just about anything that will hold a couple ounces of water
fill it with water place it in the freezer. After the water has frozen place a quarter on top of the ice then seal the container with a clear cover and return it to the freezer. You now have the simplest thaw indicator in the world. Most modern refrigerators with built in freezers can remain safe even if the power has been off for almost a day and water will start to thaw within minutes after reaching 32°f Meats wrapped in butcher paper will remain safely frozen for a while longer meat and vegetables wrapped in plastic wrap or stored in plastic bags and containers will begin to thaw at the surface shortly after water begins to thaw but will remain edible even if refrozen as long as the temperatures remained below 33 to 35°f. and did not completely thaw. Some foods such as those that have been previously cooked can still be edible even if completely thawed and refrozen. Butchered meats such as game well wrapped in several layers of butcher paper will not freezer burn as quick as store bought meats and will still be edible even it they do get mildly freezer burned.
I used a single serve jello container a discarded prescription bottle would work just fine.
If you return and find that your quarter is at the bottom of the container empty your fridge and freezer because chances are all of the food has spoiled if the quarter has only fallen about 1/4" chances are that everything except for milk and orange juice are still safe.
Remember be safe when in doubt throw it out
If the quarter is still on top either the power did not go off or was not off long enough for a thaw to start
Remember do not place your thaw indicator near the defrost element it shoule be placed well away from that but not under anything.