As sunlight hours dwindle and give way to chilly winter days, people are turning to auxiliary heat sources. Whether this source is an old fashion wood stove or a modern furnace, if it involves combustion it brings the risk of carbon monoxide. Carbon monoxide is an odorless colorless toxic gas that results from the incomplete combination of oxygen and carbon during combustion. Common sources are unvented gas or kerosene space heaters, leaking furnaces or fireplaces, back drafts from gas water heaters or gas stoves, generators, or exhaust from car engines. Make certain that any heat source is properly maintained, operated, and ventilated! Keep the car away from your building when running. It is also a good idea to make certain that the chimney is clear and in good shape before lighting that first fire of the season. A bird’s nest blocking the flue can result in more than just a headache.
Mary Knapp, Weather Data Library