hi , it could be folliculitis
or a boil . since it is red hot and hard there could be underlying pus in it.there must have been some oozing at night due to friction ,dried to form a scab. u have not mentioned the exact size of the area ,if it is large u might have to contact a doctor to get it drained because it can spread to the underlying soft tissues and even bone.
If it is smaller in size then you do hot compresses, apply antibiotic cream like mupirocin
oral antibiotic may be required.
to relieve pain
a doctor consultation is advised.