To gather snow unprotected is hell (7)
I believe the answer is:
inferno
'hell' is the definition.
('inferno' can be a synonym of 'hell')
'to gather snow unprotected' is the wordplay.
'to gather' becomes 'infer' ('infer' can be a synonym of 'gather'**).
'unprotected' says to take the centre.
The central letters of 'snow' are 'no'.
'infer'+'no'='INFERNO'
'is' is the link.
(Other definitions for inferno that I've seen before include "(Fiery) Hell" , "Dante's work" , "Hellish conflagration" , "Dante's Hell" , "(Hellish) blaze" .)