He's next to a bar, temperature becoming hot, getting rejection (5-2)
I believe the answer is:
heave ho
'rejection' is the definition.
(I've seen this before)
'he's next to a bar temperature becoming hot' is the wordplay.
'next to' means one lot of letters go next to another.
'bar temperature becoming hot' becomes 'veho' (veto, bar, with t, temperature becoming h for hot).
'he'+'a'+'veho'='HEAVE-HO'
'getting' acts as a link.
(Other definitions for heave ho that I've seen before include "Rejection" , "Call for Jack to make an effort" , "Notice" , "Sailors' cry" , "dismissal" .)