also remember carbon monoxide is heavier than air,so you need a flap low down for this gas to escape,and lying on the floor unconsious just exasebates the problem,ie;you die quicker on the floor than you would standing up,that`s why all new caravans have holes in the floor to let the carbon monoxide out,cheers,
Eric.
I'm afraid that's not true. CO is marginally less dense than air, so it will diffuse pretty well evenly throughout the air volume in a room.
Also, there's a nothing wrong with using a woodburner with the door open. It's no different from an ordinary fire on a grate. Stovax's instructions for their stoves, for example, merely point out that their stoves are less efficient with the door open and need a spark guard (which they sell as an accessory).
There shouldn't be any CO going up the chimney (or anywhere else) from any open or closed flame fire that is installed correctly and is adequately ventilated. If somebody falls over using a Calor gas stove either there's grossly inadequate ventilation, or the stove is defective.
Whether or not to use a flame heater in a workshop is a different matter, of course.