When I was a child; my sister and me, used to visited my grandmother in her village, it was located in the west of Spain; she lived in a big stone house, without heating; the kitchen had a coal heater; and while in the kitchen there was enough heat, the rest of the house was frozen.
One of that days, my sister and me were playing cards and eating a delicious cookies handmaden by my grandma, when someone picked on the door, suddenly she opened the door, it was her neighbour; they were talking for a moment and then mi grandma said us that she had already cleaned the house, and ordered us to not get dirty the house; after that she put her coat on, and went out.

Next was that I didn't realised what had happened, i only remembered that I woke up in a hospital; my parents look very relievable, my sister and me had been sleeping a cause of the gas about three hours, and they had been despaired . Luckily we recovered the health.

Fortunately it only was an anecdote in my life, but nowadays I continue turning my blood to ice when I am in a closed bedroom, so I need to open the windows or the doors for a few minutes in every hour.