Sweltering in rear of ship for PR event (5,2)
I believe the answer is:
photo op
'pr event' is the definition.
(public relations stunt)
'sweltering in rear of ship' is the wordplay.
'sweltering' becomes 'hot' (similar in meaning).
'in' means one lot of letters goes inside another.
'rear of ship' becomes 'poop' (as in the poop deck on a ship).
'hot' put inside 'poop' is 'PHOTO-OP'.
'for' acts as a link.
(Other definitions for photo op that I've seen before include "Chance for publicity" , "Chance to shoot" .)