<s>[INST] My 9 year old son woke up with a headache this morning which then developed into a fever 101.4 . Tylenol only helps until 30 minutes before his next dose. Then it goes back up. He has the chills and a fever and a stuffy nose. What could it be? Mono? Influenza? Sinus infection?Thanks, Worried Mom [/INST] Welcome to the ChatDoctorMost likely it seems to be a self limiting viral illness. Don't worry they are usually common in the kids. You can take the following measures to help him:1. Give him acetaminophen (Tylenol) or ibuprofen tablet for pain relief and fever both. You may repeat the same dose after every 6-8 hours interval if required.2. Use an antihistamine such as Chlorpheniramine or fexofenadine for stuffy nose. Also, vapor rub will be helpful.3. Use steam inhalation 2-3 times a day for congestion of sinuses. There is no need to have antibiotics or laboratory work up at present. Hopefully this will help you. For further questions, you may contact me. Take care </s>