That’s what I thought too. According to Wikipedia, concentrations of CO over 12000 ppm will lead to unconsciousness within two or three breaths, and death within a few minutes.
Since it has a greater affinity for hemoglobin than oxygen does, dragging the victim to open air and rescue breathing is not going to help a whole lot.
Note to self - no closed space, bad air rescues. Call 911, break windows, open doors. Wait.
No kidding! Good advice. I’m pretty sure however that the only way to achieve those levels are the car/suicide scenario. Never seen anything even remotely close to that when I was doing heating service work. The products of combustion would have to be totally contained.