Carbon monoxide (CO) is an invisible, odorless and tasteless gas. It’s created 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 properly or have been installed improperly.
Vehicle exhaust fumes from nearby garages, as well as fireplaces that aren’t working right may also create carbon monoxide. CO is dangerous to the body and is lethal at high levels or with long exposure.