Q: My child had Influenza A and high fever, but now experiences hypothermia at night (35.4°C) and afternoon lethargy. Should we revisit the doctor?
- Myeongchan Kim, MD
- Jul 11
- 2 min read
Updated: Jul 21
Medically reviewed by Sang Hyun Ahn, MD
Content edited by Myeongchan Kim, MD
This post is a dramatization of a question and answer session experienced by our actual medical reviewers. Please note that this content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
Question:
Hello. My child recently had Influenza A. The fever started on December 26th (38.5°C), and they were diagnosed on the 27th, receiving IV fluids and a flu shot. High fevers continued until the 28th, and they received another IV on the 29th due to a poor overall condition. Since December 30th, there has been no high fever, but their temperature drops at night (as low as 35.4°C) and only goes back up to around 36.5°C in the morning. Their condition is fine during the day, but they become very lethargic in the afternoon. Their appetite has decreased slightly, and they take long naps because they feel unusually sleepy. Should we go back to the clinic to see a doctor?
Answer:
Hello. It is completely understandable that you are worried about your child's condition after their Influenza A diagnosis, especially with the repeated low body temperatures.
Current Assessment:
Your child appears to be entering the recovery phase of the flu. While it is a positive sign that the high fevers have subsided, the low body temperature of 35.4°C requires close attention.
When to Seek Immediate Emergency Care:
Please go to the nearest emergency room immediately if you observe any of the following:
• A body temperature of 35.5°C or lower accompanied by a decreased level of consciousness or severe lethargy (difficult to wake up).
• Rapid, heavy, or labored breathing.
• Blue, pale, or gray lips and fingernails (cyanosis).
Recommendation for a Clinic Visit Today:
Because the current pattern—low temperatures at night followed by noticeable lethargy in the afternoon—is repeating, a follow-up visit to the doctor is necessary. The pediatrician will need to evaluate your child for potential post-flu complications or underlying dehydration.
Home Care Management:
Temperature Control: Dress your child in warm, comfortable clothing and maintain a cozy indoor room temperature (around 24-26°C or 75-79°F).
Hydration: Offer small, frequent sips of warm water or electrolyte beverages whenever your child is awake.
Nutrition: Provide small amounts of soft, easy-to-digest foods like porridge or warm soup.
Temperature Tracking: Measure and record your child's body temperature every 3-4 hours to show the doctor during your consultation.
While recovering from the flu typically takes 1 to 2 weeks, repeated drops in body temperature and afternoon lethargy require further medical evaluation. Please visit your pediatrician today for a thorough assessment.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
