Bipolar shift sees drop in hot water, up to a point (7)
I believe the answer is:
parboil
'drop in hot water up to a point' is the definition.
(partly boil)
'bipolar shift' is the wordplay.
'shift' indicates anagramming the letters.
'bipolar' with letters rearranged gives 'PARBOIL'.
'sees' is the link.
(Other definitions for parboil that I've seen before include "Cook in hot water briefly" , "Half-cook" , "Partially cook" , "Cook a little" , "Soften slightly in preparation for frying" .)