Is a high fever in a baby an emergency?

When your little one’s forehead feels warm, it’s natural to worry — even for experienced parents. Afterall, babies can’t tell us what’s wrong. Fortunately, in most cases, a fever is a sign that your baby’s immune system is doing its job, fighting off an infection. While it may cause discomfort, a fever alone is rarely dangerous.

Still, knowing when to monitor at home, call your pediatrician, or head to the emergency room can offer peace of mind when you need it most.

What's considered a high fever?

Infants can develop fevers quickly, and even a slight rise in temperature can feel alarming. But it’s helpful to know that their body temperature naturally fluctuates throughout the day — and can spike when they’re crying, active or bundled up.

A normal temperature range for infants is about 97–100 degrees Fahrenheit. A reading above 100.4 degrees Fahrenheit is considered a fever.

You can check your baby’s temperature using:

• Armpit (axillary reading)
• Ear (tympanic reading)
• Forehead (temporal reading)
• Rectum (for babies under three months with suspected fever, always check rectally)

Readings can vary depending on the method, so consider taking a second reading if the first doesn’t match how your baby looks or feels. It’s also important to note that rectal thermometers usually provide the most accurate number for babies under 12 months.

What causes a fever?

Causes of fever aren’t always serious. Your baby may develop a mild fever when they:

• Are teething
• Have a viral infection (like a cold)
• Recently received a vaccine

According to the National Institutes of Health, only 1% of children with a fever have a serious medical issue. If your baby is still alert, drinking fluids and producing wet diapers, it’s usually safe to monitor them at home. And when in doubt, your pediatrician is just a call away.

You can also use our Consult-A-Nurse® service. Get advice you can trust directly from experienced, licensed nurses. Call (844) 70-NURSE (844-706-8773) anytime, day or night for answers and peace of mind.

When to call your pediatrician?

There are times when a fever does need a closer look, especially in newborns. A fever can be an early sign of a more serious infection, so don’t wait. Call your pediatrician if your baby:

• Is under three months old with a fever of 100.4°F or higher — go straight to the ER
• Is three to six months old with a fever of 101°F or higher
• Is over six months old with a fever of 103°F or higher

You should also reach out if:

• The fever disappears and returns within a few days
• It lasts longer than three days
• Your baby is unusually irritable, hard to comfort, or not feeding well

You know your baby better than anyone — trust your instincts. If you're unsure about what to do next, our experienced nurses are here to help. From simple questions to more serious health concerns, you’ll always have someone to turn to for support, guidance and expert advice.

Call Consult-A-Nurse® at (844) 70-NURSE (844-706-8773) to speak with a licensed nurse — anytime, at no cost.

When to go to the emergency room?

Sometimes, a fever can’t wait for an office visit. In these cases, getting emergency care is the safest choice. Take your baby to the nearest ER immediately if they:

• Cry in a way that can’t be soothed
• Develop a red or purple rash that spreads quickly
• Have a bulging or sunken soft spot (fontanelle)
• Experience a seizure
• Have a stiff neck
• Struggle to breathe or show signs of respiratory distress
• Are difficult to wake or seem unusually drowsy
• Appear weak, unwell, or “not themselves”
• Show signs of dehydration, such as:
  • Very few wet diapers
  • No tears when crying
  • Dry mouth or lips
  • Sunken eyes or fontanelle

Diaper count guidelines for dehydration:

• Under six months: Fewer than three wet diapers in 12 hours
• Over six months: Fewer than three wet diapers in 24 hours

If you're ever unsure, it's always best to err on the side of caution and call your pediatrician or head to the ER. Early intervention can make a big difference.

Caring for a baby with a fever at home?

If your pediatrician gives the green light to care for your baby at home, here’s how to help them feel better:

• Monitor closely: Keep an eye on their temperature, behavior and appearance. If anything changes or you feel uneasy, let your pediatrician know.
• Dress lightly: Avoid bundling them in too many layers. Light clothing helps prevent overheating.
• Encourage rest: Sleep helps the immune system work best.
• Keep them hydrated: Offer breast milk, formula, or, if your baby is over six months old, small sips of water.
• Use fever reducers if needed: If your pediatrician recommends it, acetaminophen (Tylenol) is safe for babies over three months, and ibuprofen (Motrin or Advil) is OK for those over six months. Always double-check the correct dose with your doctor.

Try not to get too caught up in the thermometer reading. What matters most is how your baby is acting. If they’re alert, feeding, and staying hydrated, that’s a reassuring sign. Your calm presence and care can make a big difference in their recovery.

Trust your instincts — and reach out when you need to

Your instinct is one of the most powerful tools you have as a parent. But you shouldn’t have to go through uncertain moments alone. Consult a provider using our Consult-A-Nurse® service to ask questions and seek reassurance whenever you need it.

If you’re ever unsure or notice unusual symptoms, schedule an appointment at one of our pediatric centers across Florida. Our compassionate experts are here to support your family and help your baby feel better — fast.