From the history you ve given it can be assumed that there s an infection involving the respiratory tract. For upper respiratory tract the temperature readings you ve noted are quite high suggesting a possibility of lower respiratory tract infection like bronchopneumonia. Since it s in initial stage the cough s not productive. I would suggest you get a complete hemogram and chest X-ray AP& lateral view of your child. Following which the treatment can be decided by the pediatrician which will comprise of antibiotics, cough meds and analgesics as needed.