If you need to keep food/drinks frozen for an extended period, like for camping or a road trip, dry ice can be used to convert a cooler into a freezer!
Dry ice is a no-mess, clean way to freeze goods. It keeps food/drink frozen longer than regular ice, and it doesn't leave behind a wet, watery mess like regular ice will. Dry ice "sublimates" which means it evaporates into thin air. It's a great solution for road trips, camping, Burning Man camps, and more.
The exact temperature of your cooler (now a dry ice freezer) will depend on the amount of dry ice you use, the size of your cooler, and amount of food/drink inside the cooler. Dry ice comes in either blocks or pellets.
For this project you will need dry ice blocks. To get an estimate of how much dry ice to buy for your dry ice freezer, depending on your cooler size and the number of days you'll be using it use our Cooler Calculator.
Always handle dry ice with care and wear gloves whenever touching it. An oven mitt or towel will also work if gloves are not handy. If touched briefly, dry ice is harmless, but prolonged contact with the skin will cause injury similar to a burn.
Find more safety information on our dry ice safety page.
Wrap dry ice blocks in newspaper. This insulates the dry ice blocks, which slows down the speed at which they sublimate into air. If you don’t have a newspaper on hand, you can also wrap the blocks in a towels or with rags, but newspaper is easy. Wrap the blocks fairly tightly to protect them from air.
To increase the insulation within the cooler, you’ll want to put a layer of insulation at the bottom of the cooler, like more newspaper, towel or cardboard.
On top of the first insulation layer, add your food/drinks that you’d like to freeze.
Next, add another layer of insulation like newspaper, a towel, or a piece of cardboard. It’s best to keep this layer of insulation thin so that the cold air from the dry ice can get through to food.
Add the wrapped dry ice blocks to the cooler. For a regular 60-90 quart cooler (the typical cooler you’d take camping), you’ll be able to fit two dry ice blocks side by side, above your items that you’d like to freeze.
Add additional insulation to the cooler, above the dry ice. For this last layer of insulation, your goal is to keep as much air out of the cooler as possible -- newspaper or a towel work great. Keeping air out of the cooler slows down how fast the dry ice sublimates, so the more insulation, the better.
Each wrapped dry ice block will last 24-36 hours. The more you keep the cooler closed, and the more the cooler is insulated, the longer the dry ice will last.