It looks like a bit of frostbite.
As @azygous
suggested, apply some triple antibiotic ointment or Vetericyn to the combs. Sometimes the points (tips) may self-dub or fall off (dry up/die) but it doesn't look infected to me.
The second photos looks like maybe a small pecking wound at the back of the comb, you can put some ointment on that as well if you want to. The feather loss on the head, check for any signs of lice/mites, but if you have a rooster that could be from mounting/treading where the rooster holds on.
If the skin where the feathers are lost (if not due to mites/lice) is a bit dry looking or looks a bit irritated, you can apply ointment or A+D ointment - whatever you have.