Carbon Monoxide (CO) is produced wherever fossil fuel combustion occurs, inducing the operation of gasoline engines and heating and cooking appliances. It is invisible, odourless, tasteless and deadly. Faulty venting or even a wind shift can create a dangerous situation, [particularly in confined areas like boat cabins and sleeping quarters. CO enters the bloodstream through the lungs, blocking the oxygen your body needs. Prolonged exposure to low concentrations or short exposure to high concentrations can be fatal. Typical symptoms of Co exposure can be mistaken for the flu, seasickness, or intoxication, making accurate on board CO detection a necessity.