Q: Why does my child only have a fever during the day but a normal temperature at night?
Updated: Sep 7
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:
I wrote a post yesterday about my child's fever dropping while they sleep. On Sunday night, they only had a very mild fever, and tonight their temperature is completely normal. However, during the day on Sunday, the fever wouldn't drop below 38°C, and the same thing happened again during the day on Monday. Why does the fever only spike during the day and go away at night?
Answer:
It is actually quite common to see a pattern where a fever spikes during the day and drops at night. There are a few reasons why this happens:
Why this pattern occurs:
Natural body temperature rhythm: Our bodies naturally tend to have a higher temperature during the day due to increased physical activity and metabolic rates.
Hormonal changes: At night, an increase in cortisol hormones can help suppress the body's inflammatory response, temporarily lowering the fever.
Hydration levels: A lack of sufficient fluid intake during active daytime hours can cause the body temperature to rise.
Viral activity patterns: Certain viruses simply have patterns that make them more active or symptomatic during daytime hours.
What you can do at home right now:
Increase daytime hydration: Offer your child small sips of water every 30 minutes throughout the day.
Manage daytime activity: Avoid overly strenuous play and encourage your child to rest.
Regulate room temperature: Maintain a comfortable indoor environment between 24-26°C (75-79°F).
Use fever reducers appropriately: Only administer antipyretics (fever-reducing medication) when the temperature spikes and your child appears to be uncomfortable.
When to see a doctor:
Seek in-person evaluation from a pediatrician if:
This specific daytime fever pattern persists for more than 3 days.
Your child develops a high fever of 38.5°C or higher.
The fever is accompanied by other symptoms such as a cough, runny nose, or a rash.
Your child becomes lethargic or refuses to eat and drink.
The fact that the fever drops at night is a good sign that your child's body is actively working to recover. However, if this pattern continues or if you have any concerns about their overall condition, please consult your pediatrician for a proper examination.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
