Fever in Kids: When the Number Matters and When It Doesn’t

Seeing a high number on the thermometer can be unsettling for any parent. Fever is one of the most common reasons families reach out, and it often raises questions about how serious an illness might be and what to do next.

Understanding when the temperature itself matters and when other signs are more important can help parents make confident decisions during an illness.

What Fever Tells Us

Fever is a sign that the immune system is responding to something, most often a viral infection. In many cases, fever is part of a normal and helpful response.

The height of the fever alone does not always reflect how serious an illness is. Some children with high temperatures continue to drink, play, and interact, while others with lower temperatures may feel significantly worse.

This is why pediatricians look at the whole picture rather than the number alone.

When the Number Matters

Age matters. In infants under three months, any temperature of 100.4 F (38.0 C) or higher, ideally taken rectally, should be evaluated immediately.

In older children, context matters more. A child with a temperature of 101 F (38.3 C) can be as sick or sicker than another child with a temperature of 104 F (40 C), depending on the cause, course, or possible complications.

Children with temperatures of 106 or higher probably should be evaluated urgently.

Always check with your pediatrician if you have concerns.

A note about special situations:
If your child has a medical condition that makes fevers a higher concern, such as a history of febrile seizures or certain metabolic conditions, this general guidance may not apply. In those cases, your pediatrician may recommend a different approach.

What to Watch Along With the Temperature

When deciding how worried to be about a fever, pay close attention to how your child looks and behaves, especially when the fever comes down.

Important signs to monitor include:

• Breathing that is fast, labored, or uncomfortable

• Poor fluid intake or fewer wet diapers

• Unusual sleepiness or difficulty waking

• Severe pain or persistent crying

• A fever that lasts several days without improvement

These signs often provide more useful information than the temperature itself.

Treating Fever for Comfort

The goal of treating fever is comfort, not forcing the number back to normal. If a child is miserable, achy, or not sleeping well, fever reducers can help them rest and drink more easily.

If a child is playful, drinking, and comfortable, medication may not be necessary even if the number is higher.

Again, if your child has a medical condition that make fevers a higher concern, your pediatrician may have additional or different signs to monitor or reasons to treat a fever.

When to Reach Out

Parents should trust their instincts. If something feels different than past illnesses, or if a child seems to be worsening rather than improving, checking in early is appropriate.

Questions about fever are always reasonable. Reaching out can help clarify whether watchful waiting, an office visit, or urgent evaluation is needed.

Closing Thoughts

Fevers are common in childhood and often part of a healthy immune response. Knowing when the number itself matters and when other signs deserve more attention can make these moments less stressful.

If you are unsure or worried at any point, your pediatrician can help guide next steps and provide reassurance.

Dr. Sean Park
Lighthouse Pediatrics