Carbon monoxide (CO) is a clear, odorless and tasteless gas. It’s produced by partial fuel combustion often caused by not enough oxygen. In your house, appliances that rely on natural gas, charcoal, wood or kerosene are susceptible. Especially if they are not running accurately or have been installed incorrectly.
Vehicle exhaust fumes from nearby garages, as well as fireplaces that aren’t working right can also be a carbon monoxide source. CO is toxic to the body and is lethal at increased levels or with extended exposure.