My Child Was Playing In Our Kiddie Pool Yesterday For

My child was playing in our kiddie pool yesterday for an hour and a half in 98 degrees, ever since he has had a fever of 100-102 and he has the chills, also vomited last night but it may have been from giving him milk. He started to feel better today, temp went down and he ate and drank plenty of water but we had given ibuprofen so that may have been why, now his temp back at 100 and sleeping again not acting like self. Could this be heat exhaustion, does it last this long? We have t been anywhere in weeks so it could t be viral and he's the only one in his pool, we also put bleach in pool daily and keep it clean.