Honestly, my DD had it and had a high fever for days, wouldn't eat, only wanted to nurse around the clock, got blisters around her mouth, was MISERABLE. I gave her tylenol and ibuprofen to keep the fever down and traded off night shifts with DH because she was up all night long.
Shortly thereafter, my best friend's DD (with whom we shared childcare, so BF DD was certainly exposed by my DD all through the contagious period before the fever shows up)... phantom fever for 1 night, not all that high, slept more than usual for a few days, never even mildly cranky.
Just depends on the kid I think. I would maybe get some cool drinks and stuff to eat, because popsicles and other non acidic but cooling things feel better if they get it. And make sure you have fever relievers if you use them. Restful stuff to do on hand-dvds, books, etc. And wait. Good luck!
Happy with my DH, 2 kids, dog, fish, and frogs