How carbon monoxide poisoning works, what it does to the body

Carbon monoxide works by displacing oxygen molecules en route to the brain and other vital tissues and organs. CO molecules bind to the hemoglobin in your blood cells, forming a compound called carboxyhaemoglobin. The binding of CO to hemoglobin binds 240 times tighter than oxygen molecules, so in the presence of both oxygen and carbon monoxide, the hemoglobin will preferentially bind to the carbon monoxide molecule. This process reduces the amount of hemoglobin available to bind to oxygen and essentially starves the body of oxygen. Instead of delivering the oxygen needed by the body, the red blood cells are delivering CO molecules, which can’t be utilized by the body. It feels as if you are breathing, but more accurately, you’re breathing in air that the body can not use.

Sources:
http://www.allwebdiscounts.com/athome_06_tips.php3
http://www.medicalnewstoday.com/articles/171876.php