Carbon monoxide is a toxic gas that is produced by the incomplete burning of carbon-containing fuels, such as gasoline or natural gas. When inhaled, it binds to hemoglobin in the blood, preventing oxygen from reaching vital organs such as the brain and heart. Symptoms of carbon monoxide poisoning include headache, dizziness, weakness, nausea, and confusion. In severe cases, it can cause coma and even death. To prevent carbon monoxide poisoning, it is important to ensure proper ventilation when using fuel-burning appliances, to have carbon monoxide detectors installed in the home, and to have heating systems and other appliances checked regularly by qualified professionals.