Horrible things paraffin heaters as they can cause real problems if left unattended...
I went off to college (aged 18) and my parents had agreed to look after a large aviary of foreign finches for me through the term time...
During the coldest of weathers I used a parafin stove to keep them frost free in the 12'x8' indoor-flight.
The results were not good.... smoke filled flight killed around 60% of the birds.
My parents were up-set... but it was just one of those things.
Turning the wick too low to save on fuel can lead to smoking.