Such temperatures are cold to bear (5)

I believe the answer is:

polar

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'bear' is the definition.
(polar bear is a kind of bear)

I cannot understand how the remainder of the clue works.

(Other definitions for polar that I've seen before include "Relating to the Arctic or Antarctic" , "Of the far north or south" , "Extremely cold region" , "Of the cold regions" , "extremes of 3 or 26 [NORTH OR SOUTH]" .)

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