I live in the same area, and have had zero and 3 F temps in the last week. It can be hard to prevent frostbite on combs in those temps no matter what you do. It just happens. They will be okay in time. I have seen a lot worse that have been fine later. If you watch the emergency thread each day...
Never lance or break a blister with frostbite. Those combs have mild frostbite, and they will heal in weeks, possibly with loss of some points. Do not apply ointments or sprays, as they can add to frostbite and freeze. Do not massage the combs.