Hello! I read carefully your query and understand your concern. The way you describe it seems to be a viral infection (flu or cold). In these case fever,chills,headache,muscle aches are common symptoms. Usually viral infection are self-limiting conditions that can last 1-2 weeks. No specific treatment is needed. He need to rest,eat healthy foods mostly green vegetables,drink plenty of fluids. He can take Ibuprofen or Paracetamol for fever and pain. If these symptoms seems to worse(high fever that don t seem to decrease,cough with yellow sputum etc) or last for too long then you can consult a physician for diagnosis and treatment. Hope my answer has helped. Take care. Dr.Rovena