Warm-hearted writing by members (4)
I believe the answer is:
arms
'members' is the definition.
(arm is a kind of member)
'warm-hearted writing by' is the wordplay.
'hearted' indicates the central letters.
'writing' becomes 'ms' (abbreviation for manuscript).
'by' says to put letters next to each other.
The central letters of 'warm' are 'ar'.
'ar'+'ms'='ARMS'
(Other definitions for arms that I've seen before include "Crest - guns" , "Limbs of war" , "George Bernard Shaw play '. . . . and the Man'" , "Heraldic devices" , "pacifists won't take up" .)