Carbon Monoxide - What You Should Know Carbon Monoxide (CO) is a colorless, odorless gas produced by appliances that are improperly installed, operating poorly or inadequately adjusted. Automobiles and other carbon-based fuels can produce CO as well. When inhaled, CO blocks the ability of blood to transport oxygen and can cause serious illness to your and your family. During winter furnaces are operating and houses are sealed, a buildup of carbon monoxide is more likely to occur. People with carbon monoxide (CO) poisoning sometimes think they have the flu. They don't realize CO poisoning is making them sick because they can't see, smell, taste or hear it. If you are sick from CO poisoning, you will feel better when you go outside for fresh air. Exposure to small doses of Co over time can produce flu-like symptoms, including headache, fatigue, dizziness, nauzea, vomiting, trouble thinking and concentrating, vision problems, shortness of breath and heart palpitations. Exposure to large doses of CO leads to nausea, collapse and unconsciousness or death. If you suspect CO poisoning is affecting your family, leave your home and call our office or fire department. They know how to deal with carbon monoxide.