If you can, I'd try not to worry about it unless it goes on for over a week (or of course if it gets higher). You can give him paracetamol to reduce his temperature if you are worried about it, but it's probably just his body fighting the infection and won't do any harm. Antibiotics won't reduce a fever if it's caused by a viral infection. It's horrible when our babies are sick, Tamsin had a similar thing a week or so ago so I know exactly how you are feeling! Hope he's much better soon.