Sorry for late reply and inconvenience.
Well as you describe,it's upper respiratory tract infection.
If his fever is persistent high then Strep throat can be suspected and throat swab test should be done to rule out it and further antibiotics can be prescribed.
Mostly upper respiratory tract infections are caused by viruses and resolve in few days.
You can see your doctor if his symptoms'll not relieve with self care measures.
In the meantime hydrate him with warm liquids.
Do saline gargles.
Also start a multivitamin supplement.
Elevate his head while sleeping.
Tylenol can be added with Advil every 4-6 hourly if fever is high.
Hope this helps.
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