Carbon Monoxide, always present in fumes from the internal combustion engine, is a colorless, tasteless and odorless gas. Even minute quantities breathed over a long period of time can have serious consequences. Its effects can be cumulative and are not easily corrected. A breath of fresh air will not bring early relief - several days may be required to completely rid the body of carbon monoxide. This gas ha the ability to saturate the blood's hemoglobin and prevent the absorption of oxygen. The brain and body tissue must have oxygen to function and survive. Aircraft heaters designed to utilize the heat of engine exhaust gases are the usual source for this insidious danger. Be wary if there is a smell of exhaust fumes, especially if mental confusion, dizziness, uneasiness or headaches follow. If such symptoms develop, shut off the cabin heater, ventilate the cabin to the maximum extent possible, descend to lower altitudes where need for heat is less critical, and land as soon as possible for a thorough check of the source of the trouble. It is wise to then consult a doctor. Remember is may take several days to rid the body of carbon monoxide.

Though there are several types of relatively inexpensive detectors available today which may warn of unsafe conditions with respect to carbon monoxide in the cabin, they may not always be completely reliable, and their use should not lull one into a sense of false security.