For added protection, install detectors in furnace and utility rooms. Install detectors no higher than 4 inches and no lower than 12 inches from the ceiling or walls. CO is slightly lighter than air. Exposure to CO causes about 1500 accidental deaths and 10,000 illnesses annually. CO poisoning can be easily mis-diagnosed as the flu.
Medium exposure can produce severe throbbing headaches, drowsiness, confusion and fast heart rate.
Extreme exposure can produce unconsciousness, convulsions, heart and lung fatigue, brain damage and eventually death. CO can be present without people being aware of it. Everyone is at risk, but infants, unborn babies, people with heart problems and the elderly are more at risk than others. Since CO is by-product of combustion, it may be present anywhere fuel is burned. It can result from blocked chimneys, corroded or disconnected flues, engine exhaust, charcoal grills, gas appliances, furnaces, wood heaters, downdrafts, and reverse stacking.