Covering for one cold walkabout? (6)
I believe the answer is:
icecap
'covering' is the definition.
(I have seen 'Polar covering ' mean 'icecap' so perhaps 'covering' could also mean 'icecap')
'one cold walkabout?' is the wordplay.
'one cold' becomes 'ice' (I've seen this before).
'walkabout?' becomes 'cap' (I can't explain this - if you can you should give a lot more credence to this answer).
'ice'+'cap'='ICECAP'
'for' acts as a link.
(Other definitions for icecap that I've seen before include "Frozen polar area" , "Frozen top of mountain etc" , "Permanent coating of white on a mountain-top" , "Frozen topping" , "Permanent frozen polar cover" .)