Harold Kestenholz
Products of combustion from natural gas are mostly nitrogen, carbon dioxide, and water vapor; but a small component may be some carbon monoxide and acid vapors. It is for that reason that the exhaust is vented to the outside away from occupants within the house. Malfunctioning combustion devices with large quantities of carbon monoxide have caused death in confined spaces. Headaches, light-headedness, and loss of feeling in extremities are an indication of such poisoning.
