Fever in Children: When to Worry and When to Wait

Fevers can be scary for any parent, especially when they strike suddenly or spike overnight. But not every rise in temperature means something serious. Understanding what causes a fever and how to respond helps you stay calm and act confidently when your child feels warm.

At Tempe Primary Care in Tempe, AZ, our pediatric team supports families with expert medical services through all stages of childhood illness. Family Nurse Practitioner Frank Rosenberg, MSN, FNP-C, brings decades of clinical knowledge working in emergency medicine and rural health settings. With mentorship from pediatric-focused MDs and his distinction as an AHEC Scholar, Frank is skilled in recognizing fever patterns, urgent care needs, and when to monitor at home versus when to intervene. 

How High Is Too High for Child Fever?

A fever is your child’s natural defense against infection, but knowing what temperatures are concerning is key. Here’s a breakdown of general thresholds:

• Low-Grade Fever (100.4°F to 101.9°F): Often a response to a cold, teething, or minor virus.
• Moderate Fever (102°F to 103.9°F): This may signal a more severe viral or bacterial infection.
• High Fever (104°F or higher): Needs medical evaluation, especially if it persists over 24 hours or comes with other symptoms.

Fever is more concerning in babies under three months, where any reading above 100.4°F requires a call to Tempe Primary Care.

Signs Your Child Needs a Doctor for Fever

The number on the thermometer is just one part of the story. Pay attention to these signs that may indicate a serious condition:

• Lethargy: If your child is difficult to wake or doesn’t respond normally.
• Dehydration: Dry lips, no tears when crying, or reduced urination.
• Labored breathing: Fast or strained breathing without exertion.
• Rash: Especially if it doesn’t fade when pressed.
• Persistent vomiting or diarrhea: Can lead to rapid dehydration.

If any of these symptoms occur with a fever, it’s time to contact a pediatric provider.

Causes of Fever in Kids

Fevers can stem from a wide range of common childhood illnesses. The most frequent causes include:

• Viral infections: Colds, flu, COVID-19, and RSV.
• Ear or throat infections: Often trigger high fevers and pain.
• Urinary tract infections: Especially in toddlers.
• Post-vaccination response: A mild fever is a normal part of the immune reaction.

Identifying the source of the fever helps your pediatric provider guide treatment.

Call for Reassurance, Come in for Relief

Fever in children can be stressful, but you don’t have to navigate it alone. Call 602-283-0080 to speak with a provider or schedule a same-day pediatric visit today.