they keep moving.
Which is why boots are used 1 so they can stand still, 2 provide protection from cuts.
When it is really cold they will not stand still if they aren't moving they will lay down.
Other than that it is adaptation, thick soles, padding and lots of blood flow.
And in case anyone is wondering, toe whiskers are the tufts of fur that stick out between kitties'' toes. I imagine dogs have them too, though! My Maine Coon kitty has super fluffy toe whiskers, as do all Maine Coons, so their paws can withstand the cold!