Which poses a Question?

My galley has a twin Origo range. I fire a single burner off of
non-pressurized alcohol to perk my morning coffee. I return to the
sleeping bag and enjoy the aroma of perked coffee and the stove warming
the "Pilothouse"

Now, I've been doing this for meany years, without vents. I know the
alcohol flame does delete the oxygen level. It's worried me but not
enough to vent in cold winter air. I could use some useful comments?

I get up and dress in a sweat suit and fleece lined slipper and fire off
the other burner for home fryed potatoes with onions and remove the
coffee pot to make eggs on the other burner; still with a cloesd cabin.

As the cabin warms up I vent the main hatch, and have my second cup of
coffee.

So, how much terrible am I playing with.