Re: The effects of MO maybe?
I think it may be a combination of CO and nico. Are you lighting the coals in the same place you are smoking in? LIke a closed up room or a small room with not enough ventilation?
It sounds more like CO than nico level IMO. Although I have been wrong before.
(*Disclaimer* These are my opinions and mine alone. It does not reflect the opinions of others and is based on my personal smoking enjoyment and experience)