What Do Extreme Thirst And Fever In A Child Suggest?

Hello, my 10 year old son woke in the night extremely thirsty and again at 5:30 am. He had a fever of 101.8, body aches, severe headache, body aches, chills and what he described as pain in his shoulders, but could translate to neck pain. He kept saying how thirsty he was. No stomach issues. He hadn t eaten anything different the night before or been dehydrated. He did have about 5 mosquito bites about 6pm last night. And another large bite on Friday night assumed it was a mosquito. Also Friday night his friend had a tick attached to his leg in our grassy yard no trees. Called the dr. and she said alternate Tylenol and ibuprofen every 3 hours and see how he s doing. Yes fever went down to 99.6, but he is drinking so much and still incredibly thirsty, sleeping rather than watching tv (which is so unlike him). I am concerned that Tylenol and ibuprofen are masking the fever and that there may be a possible insect issue here - lyme? Do I need to take him to the hospital to get checked? overall his symptoms have only improved slightly with use of pain and fever reducers. Thank you!