Be quiet and keep warm (4,2)
I believe the answer is:
wrap up
I believe this clue is a double definition.
'be quiet' is the first definition.
(I've seen this before)
'keep warm' is the second definition.
(I've seen this before)
'and' is the link.
(Other definitions for wrap up that I've seen before include "Finish off - be quiet - put on warm clothes" , "Wear warm garment" , "Be quiet - fold paper round - finish" , "Bring to an end - make a parcel" , "put a sock in it" .)