Performance is physical including cold sex (7)
I believe the answer is:
recital
'performance' is the definition.
(I know that recital is a type of performance)
'physical including cold sex' is the wordplay.
'physical' becomes 'real' (I've seen this in other clues).
'including' means one lot of letters goes inside another.
'cold' becomes 'C' (eg on taps).
'sex' becomes 'it' (common euphemism).
'c'+'it'='cit'
'real' placed around 'cit' is 'RECITAL'.
'is' acts as a link.
(Other definitions for recital that I've seen before include "Article found in performance" , "Performance of music by soloist" , "Article (anag)" , "Public musical performance" , "statement of facts" .)