welcome to hcm,
as per the details u have given, YOUR FATHER IS SUFFERING FROM ACUTE FEBRILE ILLNESS.
but we should need to find out the cause for the fever
. and we have to rule out is this a VIRAL FEVER/ MALARIA/ TYPHOID
so we have to run some lab tests like
complete blood picture
blood for malaria
AFTER ALL ABOVE TESTS HAS BEEN DONE WE CAN COME TO CONCLUSION ABOUT ETIOLOGY AND WE CAN TREAT ACCORDINGLY
SO I SUGGEST U TO CONSULT A PHYSICIAN, NOW ITS VERY HARD TO SAY WITH ONLY FEVER AND SOME SYMPTOMS.