Hot and cold work reviewed by European and Sunday Times (6)
I believe the answer is:
epochs
'times' is the definition.
(both can mean periods in history)
'hot and cold work reviewed by european and sunday' is the wordplay.
I cannot quite understand how this works, but
'hot' could be 'h' (abbreviation eg on taps) and 'h' is present in the answer.
'cold' could be 'c' (eg on taps) and 'c' is found within the answer.
'european' could be 'e' (abbreviation e.g. EU) and 'e' is found within the answer.
'sunday' could be 's' and 's' is found in the answer.
The remaining letters 'po' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for epochs that I've seen before include "dates" , "Particular periods of time" , "Distinctive periods in history" , "Vast periods of time" , "Divisions of a geological period" .)