Carbon monoxide (CO) is an invisible, odorless and tasteless gas. It’s made by partial fuel combustion usually caused by not enough oxygen. In your home, appliances that consume natural gas, charcoal, wood or kerosene are susceptible. Especially if they are not running properly or have been installed wrong.
Vehicle exhaust fumes from attached garages, as well as poorly operating fireplaces could also create carbon monoxide. CO is poisonous to the body and is fatal at increased levels or with extended exposure.