> Using a stove inside an igloo made me really concerned about carbon monoxide. I see that ventilation is mentioned in the igloo article, but a mention of stoves in enclosed spaces should always include a CO warning.
The amount of CO released by a stove varies considerably, depending on the stove. You might be surprised at how they vary. The series on CO mentioned by Ken will get you started on understanding more about this, and we will be publishing a survey of canister stoves and their CO emissions quite soon.
As to igloos, the same does apply. Experienced igloo users know they have to have a vent hole in the roof. Actual CO measurements in igloos do not show a significant hazard in practice. The snow walls seem to leak a bit.
Hysterical warnings against use in a tent by some stove manufacturers do no-one any good at all however. At 10,000 ft in mid winter in a howling snow storm you are NOT going to be cooking outside, but you ARE going to be dependent on your stove for food and water, and survival. Knowledge is better than fear.
As to the PowerMax stoves like the Xtreme - well, we use them because they are so reliable in mid-winter when 'upright' canister stoves generally do not work. They are lighter and more reliable and MORE powerful than the liquid fuel alternatives. What more could you want?