May become cold: turning warmer? (6)
I believe the answer is:
cognac
'warmer?' is the definition.
(I've seen this before)
'may become cold turning' is the wordplay.
'may' becomes 'can' (synonyms).
'become' becomes 'go' (eg to go rotten is to become rotten).
'cold' becomes 'c' (eg on taps).
'turning' says the letters should be written in reverse.
'can'+'go'+'c'='cangoc'
'cangoc' written backwards gives 'COGNAC'.
(Other definitions for cognac that I've seen before include "Type of brandy" , "Good brandy" , "(French district famed for) fine brandy" , "High quality brandy" , "High-quality brandy" .)