Pure fluid gets temperature to break out (5)
I believe the answer is:
erupt
'to break out' is the definition.
(synonyms)
'pure fluid gets temperature' is the wordplay.
'fluid' indicates anagramming the letters.
'gets' means one lot of letters go next to another.
'temperature' becomes 't' (abbreviation).
'pure' with letters rearranged gives 'erup'.
'erup'+'t'='ERUPT'
(Other definitions for erupt that I've seen before include "Explode" , "Emit lava" , "Discharge" , "spout" , "go up" .)