My partner was killed by a barbecue
guardian.co.uk
guardian.co.uk
When I was about 15, over the course of a year or so, my mother gradually descended into a lethargic, apathetic mess that I vaguely ascribed to depression. Then one day my three year old sister stopped breathing while watching TV. She turned purple, collapsed, and if not for her amazing childminder calling an ambulance and giving her CPR until it arrived would have died.
Turned out, the bricks on our gas fire had been arranged incorrectly and CO (carbon monoxide) leaking into the house for over a year. My mum's bizarre mental decline was chronic CO poisoning, while my sister's episode was acute CO poisoning. My sister recovered and was fine. I'm not sure my mum ever fully recovered. Both could very easily have died.
If you have gas appliances, for the sake of your family, please get a CO detector.
http://www.backpackinglight.com/ has several scientific reports (some premium$) with specifics.
For me personally, a candle lantern is about as far as I'd go, and even "cooking in the vestibule" I'd want a good breeze.
But I don't know if this has ever actually been attempted.
I guess the outer shells must have been cooled but left a burning nugget in the center.