Purchase and pick up the dry ice less than eight hours before the play, and leave it in its container in a freezer until it is time to start the scene in which there is smoke.
Wear thick rubber or leather gloves to open the container. This will protect your hands from the dry ice, which cannot come into contact with bare skin.
Remove the dry ice with tongs and place it into one or several buckets and large bowls, depending on how widespread you want the flow of smoke to be.
Fill a pitcher with hot water and pour it over the ice to make smoke appear. Continue pouring more water over the ice slowly to increase the amount of smoke whenever you like. The dry ice will melt as the water is poured over it, creating the smoke effect.
Remove the buckets or bowls from the stage area when you want to clear the smoke and pour hot water over the remaining ice to melt it down so that you can pour it down a sink drain.