Cambridge University figure's winter warmer (6)
I believe the answer is:
mitten
'winter warmer' is the definition.
(I've seen this in another clue)
'cambridge university figure's' is the wordplay.
'cambridge university' becomes 'MIT' (MIT in Cambridge, Massachusetts).
'figure' becomes 'ten' (ten is a number).
'mit'+'ten'='MITTEN'
(Other definitions for mitten that I've seen before include "Hand warmer" , "A glove with no partitions for fingers" , "Garment" , "Fingerless glove" , "Simple glove" .)