When should I take my baby to the doctor for a fever?

For babies under 3 months, any fever of 100.4°F (38°C) or higher requires immediate medical attention. For older babies, contact a doctor if the fever is 104°F or higher, lasts more than 24 hours, or is accompanied by concerning symptoms.

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Baby Fever Checker

Q: How do I take my baby's temperature accurately?

Rectal temperature is most accurate for babies under 3 months. For older babies, temporal (forehead) or ear thermometers are convenient options. Armpit temperatures are less accurate but can be used for screening.

Enter your baby's temperature to get guidance on what to do next

Baby's Age

Temperature Reading

How was temperature taken?

Additional Symptoms (check all that apply)

Unusually sleepy or hard to wake Unexplained rash Difficulty breathing Persistent vomiting Inconsolable crying

Important: This tool provides general guidance based on common pediatric recommendations. It is NOT a substitute for professional medical advice. When in doubt, always contact your pediatrician or seek emergency care.

Frequently Asked Questions About Baby Fever

What temperature is considered a fever in babies?

A rectal temperature of 100.4°F (38°C) or higher is considered a fever in babies. For oral or armpit readings, 99.5°F (37.5°C) or higher typically indicates a fever. Rectal temperatures are the most accurate for infants.

When should I call the doctor for my baby's fever?

Call immediately if: Your baby is under 3 months with any fever 100.4°F or higher, has a fever over 104°F at any age, has a fever with a rash, is extremely lethargic, or has difficulty breathing. For babies 3-6 months, call if fever reaches 102°F or lasts more than 24 hours.

How can I help my baby feel better with a fever?

Keep your baby hydrated with frequent feedings. Dress them in light clothing and keep the room comfortable. A lukewarm bath can help. For babies over 3 months, infant acetaminophen (Tylenol) may be used - consult your pediatrician for dosing. Never give aspirin to children.

What's the most accurate way to take a baby's temperature?

Rectal temperature is the gold standard for babies under 3 months. For older babies, temporal (forehead) or ear thermometers are convenient and reasonably accurate. Armpit temperatures are less accurate and may read 1-2°F lower than actual body temperature.

Recommended Thermometers

An accurate thermometer is essential for monitoring your baby's health. Here are our top picks:

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Frida Baby 3-in-1 Thermometer

Rectal, oral & underarm readings. Our top pick for accuracy.