What takes warmth out of screwy Gen X heartache (4,9)
I believe the answer is:
heat exchanger
'what takes warmth out' is the definition.
'screwy gen x heartache' is the wordplay.
'screwy' indicates an anagram.
'gen'+'x'+'heartache'='genxheartache'
'genxheartache' anagrammed gives 'HEAT EXCHANGER'.
'of' acts as a link.
(Other definitions for heat exchanger that I've seen before include "Device used in cooling systems" , "What may be used to cool a fluid" .)