Dear Kamalesh Banerjee I think the main cause of high temp of your baby is dehydration
Just continue with antibiotics as your doctotor prescribed and complete the course.
Ror temp you can give the baby Paracetamol
Syrup (500mgm/5ml) 2.5 mls three times daily.
Get some Electrol sachets and dissolve 1 sachet in 300mls od boiled and cooled water and feed
the baby frequently. I wish him speedy recovery. Kindest regards Dr. S.K.Mukherjee