Q: My child is in a deep sleep and won't wake up after a 40°C fever. Is this normal?

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:

My child cannot wake up from a deep sleep after having a high fever. We visited the doctor on Sunday and were prescribed antibiotics and fever reducers for a slightly swollen throat and a runny nose. At dawn, the fever spiked to 40°C (104°F), so I gave them the fever reducer. By noon today, their temperature dropped to normal, and their overall condition was great—they were eating and playing just like normal. However, they started taking a nap at 3 PM and haven't woken up yet. When I try to wake them, they just get annoyed and fall right back into a deep sleep. Is this okay?

Answer:

A long nap after a high fever can be worrying, but it is often a natural part of a child's recovery process.

Based on what you shared, here is an evaluation of your child's current status:

• Normal temperature + good condition earlier: This is a very positive sign.

• Recovering from a 40°C fever: Fighting off a high fever takes a massive amount of energy, so the body naturally requires deep sleep to heal.

• Getting annoyed when woken: While frustrating, this is actually good news—it proves your child is conscious and responsive.

Things you should check right now:

1. Is their breathing regular? (Observe their chest for 1 full minute).

2. Is their facial skin color normal and healthy?

3. Is their body resting in a natural posture (not completely limp or unresponsive)?

⚠️ Go to the Emergency Room immediately if you notice any of the following:

• There is absolutely no reaction when you try to wake them.

• Their breathing is irregular, labored, or unusually fast.

• Their lips or face appear pale or bluish.

• They do not wake up for more than 6 hours.

Generally, 3 to 4 hours of deep sleep after a severe fever is perfectly normal. However, if your child does not wake up after a few hours, try to forcefully wake them to check their level of consciousness and offer them a few sips of water. Continue giving the prescribed medications as directed. If your child still lacks energy or appears unusually lethargic tomorrow morning, please visit your pediatrician for a follow-up examination.

For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.

fevercoach.us

Apple App Store

Google Play

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