Kids & Fevers: When to Worry, When to Stay Calm

As much as you try to wash your kid’s hands, it’s inevitable…your little one will get a fever. The questions I’m most often asked from parents: How should we measure a fever? When should we call the doctor?

I recently shared tips with the Austin American-Statesman and thought I’d pass them on to you.

How should a fever be measured? For kids under one, rectal temps are the most accurate and easy to do. For kids over age 3 or so, oral temps are best. Kids ages 1-3 are tricky. Any way you take their temp it will be a challenge and a rough estimate at best. Temporal artery scanner (taken on the side of the forehead) is the simplest, quickest and most accurate for a squirmy toddler. Taking it under the arm (axillary) will also do—but whatever method you choose, let the doctor know HOW you took the temperature and what the thermometer actually read. (Don’t do any math equation with the results.) 

When should you see a doctor?  We wrote about this in a past blog. The same guidance applies. Fever rules vary by age…and babies are the most worrisome. Seek immediate medical attention for…

Age 0-4 weeks: Any fever of 100.4 or higher taken rectally IS an emergency in this age group. It requires immediate evaluation done in a hospital setting. That is because they are at risk for bacterial infections due to issues surrounding birth or abnormalities a baby might be born with (e.g. kidney/bladder issues).

Age 4 weeks-3 months: Any fever (100.4 or higher) in this age group also requires immediate medical attention to determine the source of the fever.

Age 3 months to 6 months: Fever of 102 or greater needs medical evaluation or fever AND one of these:

    • lasting more than 3 days in a row
    • a new fever after recent illness
    • no obvious symptoms of viral illness with the fever
    • unconsolable
    • petechiae rash (purple flat specks–see our rash-o-rama in bonus material on our website)

Age 6 months and up: Fever of 104 or greater or any of those symptoms listed above with fever.

- Dr. Ari Brown, MD


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