You can't see it. You can't smell it. You can't taste it. You can't feel it. But it is responsible for more poisoning deaths in the United States each year than anything but heroin. What is it? Carbon monoxide gas!
Who is at the biggest risk? Adolescent boys and college students (Pediatric News. 33(8):8, 1999). Carbon monoxide is a byproduct of combustion. Tinkering with the engine of a car, motorcycle, or lawn mower in a closed garage is the biggest danger. Stoves or heaters that burn gas, propane, kerosene, wood, or charcoal, produce carbon monoxide, which can accumulate if there isn't adequate ventilation. At least consider the possibility of carbon monoxide poisoning whenever you run across the first signs of poisoning -- headache, nausea and fatigue. Poisoned people usually believe they have the flu. Often until it is too late.