A smudge pot (also known as a choofa or orchard heater) is an oil-burning device used to prevent frost on fruit trees. Usually a smudge pot has a large round base with a chimney coming out of the middle of the base. The smudge pot is placed between trees in an orchard. The burning oil creates heat, smoke, carbon dioxide, and water vapor. It was believed that this oil burning heater would help keep the orchard from cooling too much during the cold snaps.