Re: CO POISIONING!
If your interested in knowing how much CO you are being exposed to, I would suggest buying a CO monitor/alarm. Living in a northern climate, with winter coming on and being faced with 3-4 months of not not being able to "open up the house" I decided to buy one. I got it at Wal-Mart for about $25. It has a digital display that shows CO in PPM.
What I found basically, is that one session (regardles of brand/type of coals) doesn't raise the CO level significantly however the level will stay raised for a long time and if you have multiple sessions, the CO level can become rather high.