Carbon monoxide is a dangerous gas that you cannot smell or see. It is produced as a common by-product of the combustion (burning) of fossil fuels. Most fuel burning equipment (natural gas, gasoline, propane, fuel oil, and wood), if properly installed and maintained, produces little carbon monoxide. The by-products of combustion are usually safely vented to the outside. However, if there is a shortage of oxygen to the burner, or the venting is not adequate, carbon monoxide production can increase to dangerous levels. Common sources of carbon monoxide include gasoline engines running in closed garages, fuel-burning space heaters or water heaters with improper venting, and blocked chimneys or vent pipes.
If you breathe in carbon monoxide, it enters your bloodstream and robs oxygen from blood cells. This is called carbon monoxide poisoning.Physical symptoms of carbon monoxide poisoning vary, depending on the amount in the bloodstream. The higher the concentration, the higher the danger.
Since many of the symptoms of carbon monoxide poisoning are similar to those of the flu, food poisoning or other illnesses, you may not think carbon monoxide poisoning could be the cause.
If you or someone in your home has these symptoms, or if you have any doubts, get out of the house right away. Call 911, your local fire department, or local emergency medical service from a nearby phone.