Dry ice
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Dry ice can be used to make a deep freeze cooler that will keep its contents frozen for at least 4-5 days. Any regular cooler will work fine. Here are some particular tips for using dry ice in a cooler:
- Add the dry ice to the bottom of your cooler and layer your food on top.
- As with regular coolers, but even more so, keep your dry ice cooler shut tight and out of the sun. Both opening it and leaving it in the sun will dramatically increase the rate at which the dry ice evaporates.
- Anything in your dry ice cooler will be completely frozen. This is bad for many vegetables, though some fruits such as strawberries and grapes do well frozen.
- Anything not in a well sealed container can take on an extremely bad flavor when kept in a dry ice cooler.
Safety
- DO NOT KEEP DRY ICE OR A DRY ICE COOLER IN AN ENCLOSED AREA. Doing so presents a suffocation risk. Dry ice is frozen carbon dioxide. When it "melts" it transforms directly into carbon dioxide which can fill an enclosed area and suffocate anyone in it. This includes tents and cars carrying dry ice.
- Avoid touching dry ice. It is cold enough to freeze your skin, producing blisters.
- More dry ice safety info: http://www.wrh.noaa.gov/vef/kids/dryice.php
