What would cause chills, sleepiness, couldn't stay awake, all in and hour or two in the early evening, then high fever 102-103-102 emergency room, blood work OK urine OK Chest x ray OK. Temp went down to 101 and was discharged from emergency room at 1:45 AM Hospital thought dehydration and they said possible infection but didn't know what. OK now but would like to know what could have caused it.