The others finding flu treatment relaxing (7)
I believe the answer is:
restful
'relaxing' is the definition.
(I know that relaxing can be written as restful)
'the others finding flu treatment' is the wordplay.
'the others' becomes 'rest' (other people are the rest).
'finding' is a charade indicator (letters next to each other).
'treatment' indicates anagramming the letters (letters treated or processed differently).
'flu' anagrammed gives 'ful'.
'rest'+'ful'='RESTFUL'
(Other definitions for restful that I've seen before include "Soothing is required" , "Still - calming" , "Quiet, soothing" , "Tranquil - fluster (anag)" , "Sedative" .)