No hero takes care of a room full of the sick (6)
I believe the answer is:
coward
'no hero' is the definition.
(a coward is not a hero)
'care of a room full of the sick' is the wordplay.
'care of' becomes 'co' (c/o can mean 'care of' when addressing mail).
'a room full of the sick' becomes 'ward' (hospital ward).
'co'+'ward'='COWARD'
'takes' acts as a link.
(Other definitions for coward that I've seen before include "whose encounter was briefly filmed" , "Someone lacking courage" , "Person without courage" , "Yellow type" , "Poltroon" .)