Carbon Monoxide is odorless and colorless. A battery-operated detector is the only reliable way to know it is present in your home. What is Carbon Monoxide Poisoning? Carbon monoxide (CO) is a highly toxic, invisible gas produced whenever you burn fuel—including gas, wood, propane, or charcoal. The "Silent Killer": Because you cannot see, smell, or taste it, CO can reach deadly levels before you realize there is a problem. When inhaled, CO binds to your red blood cells (hemoglobin) over 200 times more strongly than oxygen does, effectively starving your vital organs of oxygen from the inside out. Symptoms: The "Flu Without a Fever" CO poisoning is notoriously difficult to diagnose because its early symptoms often mimic a common cold, the flu, or even food poisoning. Common signs include: Dull Headache: Typically the first and most common early warning sign. Dizziness & Phy...