my son is 2 and he had a short flu last week where he threw up 5 times overnight and next day felt well enough to eat a little and drink but had diarrhea . two days of weird stools that i thought was just because the virus was making its way through his system. then sunday night he wakes up soaked in his sweat and screaming. this happened 5 times over the course of the night. in the morning he seemed a little off but not bad until another episode came on and he started crying and screaming owie owie and pointing to his back. i thought maybe it was his kidneys. went to emergency and his urine checked out ok and after a dose of advil , he was playing and jumping....today he has been fine and without fever but he has developed a heat rash on both shoulders. are they connected at all? he normally has normal skin....