Carbon monoxide (CO) is a colorless, odorless and tasteless gas. It’s produced by partial fuel combustion frequently caused by a lack of oxygen. In your house, appliances that need natural gas, charcoal, wood or kerosene are susceptible. Especially if they are not working accurately or have been installed wrong.
Vehicle exhaust fumes from attached garages, as well as poorly operating fireplaces could also create carbon monoxide. CO is dangerous to the body and is fatal at increased levels or with prolonged exposure.