Fever in kids: when to worry and when to wait

A fever is the body doing its job — turning up the heat to fight an infection. Most fevers in healthy kids are not dangerous on their own. What matters far more than the number on the thermometer is how your child looks and acts.

Here is a pediatrician’s quick guide.

What counts as a fever?

A rectal, oral, or temporal-artery reading of 100.4°F (38°C) or higher is a fever. Underarm temperatures read about a degree low, so add 1°F to underarm readings.

What to do at home

For a child who is otherwise drinking, peeing, and reasonably comfortable:

• Fluids first. Small, frequent sips of water, breast milk, formula, or an electrolyte drink.
• Dress lightly. Bundling a feverish child traps heat. One thin layer is enough.
• Medicine if uncomfortable. Acetaminophen (Tylenol) is okay from birth at the right weight-based dose. Ibuprofen (Motrin / Advil) is okay from 6 months and older, never younger. Follow the dosing on the package — or call us.
• Never give aspirin to children. It is linked to a rare but serious condition called Reye’s syndrome.

You do not have to break the fever to “feel like you’re doing something.” Bringing the temperature from 103° to 101° will not change the course of the illness — it just makes your child a little more comfortable.

Call us — same day

Call the office (or our after-hours triage line) for any of these:

• Any fever in a baby under 3 months — always urgent
• Fever above 104°F in a child of any age
• Fever lasting more than 3 days, or one that returns after being gone for a day
• A rash that doesn’t blanch (turn white) when you press on it
• Stiff neck, severe headache, or sensitivity to light
• Repeated vomiting or refusing all fluids
• Very few wet diapers / fewer trips to the bathroom (signs of dehydration)
• Your child is unusually sleepy, very floppy, or hard to wake
• You just feel that something is wrong

Go to the ER — or call 911

• Trouble breathing or fast, hard breathing that doesn’t ease between fevers
• A seizure (febrile seizure) that lasts more than 5 minutes, or any seizure in a child who has not had one before
• Blue or grey lips or fingertips
• A child who is unresponsive

The bottom line

In a child older than 3 months who is otherwise alert, drinking, and reasonably playful, fever is a symptom — not an emergency. It is your child’s immune system at work.

But you know your child. If something feels off — even with a normal temperature — call us. That is exactly what we are here for.

This article is for general educational purposes and is not a substitute for advice from your child’s pediatrician.