Q: My child has a 40°C fever that won't go down with cross-dosing antipyretics. The flu test was negative. What should I do?

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:

It has been a while since my child had a fever. Usually, cross-dosing antipyretics brings it right down, but the fever started yesterday morning, and today it peaked at 40°C, with the lowest being around 39°C. This is happening even though I am cross-dosing every 2 hours using a dose that is roughly half of the child's body weight. We went to the clinic this morning, received a negative flu test, and the doctor said it looks like a viral infection. We only received cough and phlegm medicine, no antibiotics.

Should we go back to the doctor tomorrow? Is cross-dosing the only thing I can do right now? My child also complains of a headache, a sore throat, and a stinging tongue. What else can I do to help my child right now?

Answer:

It must be very worrying that your child's high fever has continued since yesterday and the response to the fever reducers is weak.

[Danger Signs to Check Immediately]

If you observe any of the following signs, please visit the emergency room, even if it is tonight:

• Difficulty breathing, or the area under the ribs retracting when inhaling.

• The child is extremely lethargic, difficult to wake up, or cannot make eye contact.

• No urination for more than 8 hours.

• Dry lips and tongue, crying without tears, or decreased skin elasticity (signs of dehydration).

• A stiff neck (the child cannot touch their chin to their chest).

• A severe headache accompanied by repeated vomiting.

[What to Do at Home Right Now]

1. Recheck the cross-dosing intervals and dosage:

• Leave at least a 2 to 3-hour gap between giving acetaminophen and ibuprofen.

• Follow the proper daily interval for each specific medication: 4 to 6 hours for acetaminophen, and 6 to 8 hours for ibuprofen.

• Giving a dose that is exactly "half of the body weight" might be insufficient depending on the specific concentration of the medicine. Reconfirm the prescribed dosage guidelines or consult a pharmacist to ensure you are giving the correct weight-based dose.

1. Offer frequent, small amounts of fluids:

• Offer a sip or two of fluids every 5 to 10 minutes. Electrolyte drinks, thin rice gruel, or soft foods are good options.

• To soothe the sore throat: Warm water with honey (only if the child is over 1 year old) or cold treats like ice cream and sherbet can help ease the pain.

1. Avoid physical cooling methods:

• Do not use tepid water sponging, ice packs, or rubbing alcohol. These can induce shivering and actually raise the body's core temperature.

• Dress the child in a single, light layer of clothing and maintain a comfortable room temperature of 22–24°C (71–75°F).

1. Keep a symptom log:

• Write down the times of the highest and lowest temperatures, the type/dose/time of fever reducers given, urination frequency, amount eaten, and any behavioral changes. This will be very helpful to show the doctor tomorrow.

[What to Ask at Tomorrow's Clinic Visit]

• "The flu test was negative, but the high fever has lasted over 48 hours with a poor response to antipyretics. Are other tests (such as blood, urine, or a chest X-ray) necessary?"

• "Could you verify if the medication dosage I am giving is correct based on my child's exact weight?"

• "My child has a severe sore throat and a stinging tongue. Could this be stomatitis (mouth ulcers) or another specific viral cause?"

In the early stages of a viral infection, a high fever can persist for 2 to 3 days. However, because the response to the fever reducers is weak and multiple symptoms are overlapping, an in-person medical re-evaluation is absolutely necessary tomorrow. Please monitor your child closely tonight focusing on the danger signs checklist. If any of the danger signs appear, seek immediate medical evaluation at the nearest emergency room.

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

🌐 Also available in: Español · 한국어