Gas not even cool when compressed (6,8)
I believe the answer is:
carbon monoxide
'gas' is the definition.
(I've seen this before)
'not even cool when compressed' is the wordplay.
I cannot quite see how this works, but
'not' could be 'no' (I've seen this in other clues) and 'no' is found in the answer.
'when' could be 'on' (I've seen this in other clues) and 'on' is found in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for carbon monoxide that I've seen before include "CO" , "inspired to kill" , "Toxic gas" , "POISON" .)