If you have any kind of gas heat get a carbon monoxide detector that starts reading at one part per million!!!! I have been so sick and I found a old detector that we had and right away it measured 99. because we are already sick we might overlook these signs and symptoms.....Severe headache, nausea and/or vomiting, weakness, fatigue, confusion. Of course with severe cases unconsciousness, AND THEN DEATH. You might think that you have the flu or are getting sicker with FM/CFS and stay home more, and therefore have more exposure than other family members! Please be aware! Hugs, Tam PLEASE KEEP BUMPED FOR EVERYONE TO SEE!