One who treats wounds - in the chest? (7)
I believe the answer is:
dresser
This clue is a double definition.
'one who treats wounds' is the first definition.
(I've seen this before)
'the chest?' is the second definition.
(synonyms)
'in' acts as a link.
(Other definitions for dresser that I've seen before include "behind the scenes" , "employed off stage" , "Cabinet with shelves" , "one employed backstage" , "medical student" .)