Carbon monoxide (CO) is a colorless, odorless and tasteless gas. It’s made by insufficient fuel combustion often caused by insufficient oxygen. In your house, appliances that consume natural gas, charcoal, wood or kerosene are susceptible. Especially if they are not running accurately or have been installed incorrectly.
Vehicle exhaust fumes from neighboring garages, as well as fireplaces that aren’t working right can also produce carbon monoxide. CO is toxic to the body and is deadly at increased levels or with long exposure.