Known as the "silent killer," carbon monoxide poisoning has been in the news and has been the focus of several in-depth reports. The media has not exaggerated the importance of being aware of the risks of this dangerous gas. Carbon monoxide (CO) is an invisible, odorless, colorless gas created when fossil fuels such as gasoline, wood, or coal, burn incompletely. In the home, gas heating and cooking equipment, fireplaces, and gas water heaters, are possible sources of CO. Vehicles running in attached garages also produce dangerous levels of CO.
In the bloodstream, CO prevents oxygen from combining with hemoglobin and restricts the oxygen delivery to vital organs.
CO poisoning can cause a number of symptoms, depending on the length and severity of exposure. Mild exposure can
result in a slight headache, nausea, vomiting, and fatigue ("flu-like" symptoms). Medium exposure can produce headaches, drowsiness, confusion, and fast heart rate. Extreme exposure can produce unconsciousness, convulsions, heart and lung fatigue, brain damage, and 
eventually death.
The best defenses against CO poisoning are safe use of vehicles, particularly in attached garages, and proper installation, use and maintenance of household gas cooking and heating equipment. Appliances should be checked annually by trained technicians to ensure they are working properly. Installation of CO detectors in homes is also a move to consider. These detectors can provide early warning of accumulating CO and can alert residents to a possible dangerous situation before symptoms are noticed.
CO detectors are very sensitive and may occasionally give a false indication of a problem. It is important
to evaluate the conditions of the occupants when an alarm occurs. If ANY symptoms of CO poisoning are present, the building should be immediately and completely evacuated and the fire department should be summoned by calling 9-1-1.
If no indications of CO poisoning are present, the detector may be reset. If the detector activates again, call the fire department via 9-1-1.