My mother was diagnosed with overlap syndrome but still she has low grade fever ranges from 36.7 to 37.4 c after treatment. what should we do?

Overlap not helpful: Hi Ruby 290. 'Overlap Syndrome' is a Rheumatologists way of saying your mother has signs/symptoms of two of their favored diagnoses...which probably actually means her condition hasn't been well studied. I would be sure you are working with an academic person at a tertiary center, someone who has time and compassion to begin and supervise a disease modifying program (DMARD) for her.