Kept perfectly cool (4)
I believe the answer is:
iced
This clue might be a double definition.
'kept perfectly' is the first definition.
Although both the answer and definition are past participle verbs, I don't understand how they can define each other.
'cool' is the second definition.
(similar in meaning)
Can you help me to learn more?
(Other definitions for iced that I've seen before include "Frozen, chilled" , "Decorated; killed" , "Core; card; organ" , "Chilled - killed" , "found thus in freezer?" .)