Carbon monoxide (CO) is a colorless and odorless gas that is formed from the incomplete combustion of carbon-containing substances. It is highly toxic and can be deadly when inhaled in high concentrations. Carbon monoxide is produced by vehicles, industrial processes, and the burning of fossil fuels. It binds to hemoglobin in the blood, reducing its ability to carry oxygen, leading to carbon monoxide poisoning. Symptoms of carbon monoxide poisoning include headaches, dizziness, nausea, and confusion. It is important to have proper ventilation and carbon monoxide detectors in place to prevent exposure to this dangerous gas.