Can I use dry ice in a standard cooler?

Yes, but never seal it tight — dry ice sublimates into CO2 gas, and pressure can crack the plastic or pop the lid. Leave the drain plug open or prop the lid ajar. Line the bottom with cardboard to prevent cold damage, and place dry ice on top of items so cold sinks down. A 10-pound block lasts about 24–36 hours in a standard 50-quart cooler if opened sparingly.