Barryp said
"Another interesting Zen point: “The more a flame is disrupted, the more CO is produced. Placing a pot, or anything else for that matter, on a stove drastically increased CO production. So relatively speaking to the effects of CO production, using a stove to heat a tent is far less dangerous than using it to melt snow or cook with.”

An article I was reading in an Australian group with a lot of climbers was saying that modifying your white gas stove by raising the pots above the top of the normal flame pretty much eliminates CO production and makes them safe for use in tents.

I personally do not use alcohol stoves but I have noticed that they always have tall flames and thats why I was thinking that every alcohol stove has its flame majorly interrupted by the pot. The zen article said that heating your tent without a pot would produce far less CO than any use with a pan on it. Onereason I don't cook in my tent with white gas (or liquid fuel of any kind) is the smell of priming and the toxic fumes after extinguishing the flame. I cook in my tent with my Coleman Xtreme compressed gas stove with liquid fuel feed and ventilate well. As far as I know - popular alcohol stoves do not have air intakes to premix O2 but depend on it happening under the pot, thus pressurized stoves with premix air intakes should be safer by burning with a shorter flam.

From the zen article "Yellow flames suggest incomplete combustion's and generally associated with production of large amounts of CO. If you get yellow flames, you should consider shutting off your stove, possibly cleaning it (special attention given to the jet), replacing the fuel, and/or making sure it is sufficiently pressurized instead of subjecting yourself to deadly levels of CO. "
Jim