Uncle Marvo wrote:
Ventilate it. You should provide an escape route for the vapour. I wouldn't
use a paraffin heater in a greenhouse myself but, if you do, be aware that
the vapour is heavier than air (although when it is hot and leaves the wick,
if there is one, it will initially rise) and it will eventually reach a
level where it finds the source of ignition (the heater itself) and blow
back (ie go bang).

When we were poor, we used to have an aladin parafin heater. It leaved
at the end of our bed (a matress on the floor) and I used to kick it
with my foot so that the flap would cover the wig and then switch it
off.

One day, I went to bed by myself - D was working late - and as usual I
kicked the aladin and fell asleep. Some hours later, I do remember
smelling the parafin, but it usually smelt a bit, and I kept sinking
deaper into my duvet. But then I was woken up by a crazy D, yelling my
name and struggling trying to open the window. When I opened my eyes I
couldn't see, for the smoke was so thick and I couldn't breeze either.

It is thanks to my Angel up there and D returning when he did. Or I
don't think I'll be there to tell the tale....