Fever with teething?

Lil one has just overcome a bug so been unwell all last week finally back to normal last 2 days and now feels like back to square one he woke up at 1am and his skin felt like it was on fire!!! Hes droooling loadsssss and just constantly crying and whining and cant settle him for long, anyone else having this with the back teeth? As presuming its his teeth cause of the amount of drooling, doing everything calpol, teething stuff etc but not making a difference :( it’s his birthday tomorrow and sad he’s gunna have a rubbish day cause he won’t be his normal bubbly self :( xx