We just received this email from the Utah Division of Emergency Management safety officer Matt Beaudry:
You may have recently fired up the furnace for the upcoming winter season.
Please be mindful of the heating sources in your home that can release carbon monoxide. CO is an odorless and colorless gas that can be lethal.
Symptoms of CO poisoning include drowsiness or unconsciousness, nausea, vomiting, headache and flu-like symptoms.
If you suspect CO poisoning in your home get everyone out, call 911, and wait for the fire department. As counter-intuitive as it seems, do NOT ventilate your house. As long as everyone is out (pets too!) keep your house sealed so that the fire guys can get an accurate reading with their gas sniffers to determine if CO really is in play.
It is very important to install carbon monoxide detectors near or in each separate sleeping area. For added protection, placement of an additional detector at least 15-20 feet away from the furnace or fuel burning heat sources is recommended. Also, install carbon monoxide detectors at least 10 feet from sources of humidity like bathrooms and showers. In two story houses, install one carbon monoxide alarm on each level of the home. If you have a basement, carbon monoxide detector placement is recommended at the top of the basement stairs.
More FAQs for CO detectors can be answered at this site