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