A buildup of carbon monoxide in the blood prohibits the absorption of oxygen in the blood system.
Symptoms are flu-like, including nausea, dizziness and headaches.
It is an odorless, colorless gas. Walden said carbon monoxide can come from anything from cigarette smoke to heating fuel. Walden said the main causes of the serious gas are improperly used heating systems and malfunctioning equipment. The way people can prevent the problem is to have heating systems properly installed, used and maintained annually by professionals. Walden stressed the importance of having systems professionally maintained because a homeowner may not be as thorough as a professional.