Cool pot, somewhere to keep flask? (3,6)
I believe the answer is:
hip pocket
'somewhere to keep flask?' is the definition.
'cool pot' is the wordplay.
'cool' becomes 'hip'.
'pot' becomes 'pocket' (I've seen this before**).
'hip'+'pocket'='HIP-POCKET'
(Other definitions for hip pocket that I've seen before include "this found in one's trousers" , "pouch for personal keys?" , "Wallet depository?" .)