Hi,
I am sorry your family is going through an ordeal.
Your father has pneumonia. One of the symptoms of pneumonia is a fever. Your father could be having viral or bacterial infection.
You have to trust the doctors in the hospital or maybe you can engage a private specialist in endocrine systems and another one in pulmonary systems to see your father. Or transfer your father to another hospital if you find the service lacking.
All the best. God can heal your dad. Jesus is the healer. Miracles can happen when we call upon Jesus.
I am not a MD, but I have scanned through medical textbooks before.