Way back when I was young they taught about carbon monoxide in elementary school. But that was not in America... 
Bizman and TC hit the nail on the head. The public should be educated about the hazards of CO. For 38 years I directed the Iron making operations of the largest producers of CO.
Blast furnaces. The process of smelting Iron Ore produces HUGE quantities of CO. As a matter of fact they produce 100s' of thousands of cubic feet per minute! The gas that blast
furnaces produce is used to fuel Boiler Houses and the Stoves that heat the wind that blow through the stoves to temps of up to 2200 degrees F. The Steam that is produced by
the boiler house powers a turbine blower that creates the "wind" that is then heated by the stoves. Blast furnaces will produce around 200K cfm of CO per min. We try to harness it and contain it,
but sometimes mechanical and electrical failures can spread an entire area with CO to the rate of over 500 parts per million. Deadly levels and explosive levels. I have seen CO completely
destroy a dust catcher, (a huge cylindrical vessel around 50 feet high) and completely blow off bulkheads that are 92 inches in circumference with approximately 140 1 inch bolts holding
the bulkhead in place and tossing it over 200 yards bouncing off I beams and going through a house trailer 125 yards away...and the bulkhead kept on going. The reason OSHA got involved
with CO detection and limits is this. Around 1977 a stovetender (one who heats and puts stoves ON the furnace and who takes them OFF the furnace to heat them) was spotted down on the
stove deck. A co-worker went out to see what was wrong went down also because of the CO. Both were then spotted down and, in the end I am sorry to say 9 men succumbed to CO poisoning.
I remember to this day this accident. All who work on Blast furnaces are a brotherhood. There are few of us that do this work and the knowledge of what goes on working on blast furnaces is
basically only known to those of us that make iron. There are probably more attorneys in a town of 80,000 then there are of us in North America. Point is YOU DON"T KNOW how deadly CO
can be. Please use CO monitors! At the right levels your home can literally explode. CO is odorless, you can't smell it. I have been gassed and thanks to CO monitoring at work and knowing the symptoms
(one can be completely conscious being "gassed" but laying there with no control over your muscle system, motionless. You are lying there realizing you are about to die and you can do nothing about it.)
Although now retired, I still have the OSHA book at home. This reminds me that many good men died because of CO poisoning. PLEASE USE CO MONITORS IN YOUR HOME!