Here’s the short answer, because it’s the one parents come looking for at two in the morning: teething can make your baby feel a little warm, but it does not cause a true fever. A true fever is a rectal temperature of 100.4°F (38°C) or higher, and when you see a number like that, the cause is almost always something other than a tooth coming in. We say this gently, because we’ve sat across from plenty of worried parents who were sure the molars were to blame. Most of the time, the teeth are innocent bystanders.
What teething really does
Teething is uncomfortable, no question. As a tooth pushes through the gum, your baby lets you know about it. The genuine signs are local and mild: more drooling than usual, a strong urge to gnaw on fingers and toys, fussiness, swollen or red gums where the tooth is arriving, and sleep that’s a bit more broken. Some babies feel a touch warm, but teething stays below the fever line. The best available evidence, including a large pooled analysis published in Pediatrics, shows erupting teeth are associated with at most a slight rise in temperature, one that stays below the fever line.
What teething does not do is make your baby truly sick. It doesn’t cause vomiting, diarrhea, a hacking cough, congestion, or a fever. Those symptoms get pinned on teething because teething happens during the same months babies catch their first colds and stomach bugs, but two things happening at once isn’t the same as one causing the other. When a teething baby also runs 101 or 102, what we usually have is a teething baby who also caught a virus.
The 100.4°F line
If you remember one number from this whole piece, make it 100.4°F, measured rectally. That’s where we stop calling a temperature “warm” and start calling it a fever. We point to the rectal reading on purpose, because in babies it’s the most accurate. Armpit readings run low, and forehead and ear thermometers are convenient but less reliable, and a borderline number is exactly when accuracy counts. Below 100.4, in a baby over three months who’s acting like themselves, a slightly high reading during teething is generally nothing to chase. At or above it, think of it as a fever that needs explaining, not a side effect of a tooth.
A lot of the pages answering this question are written by dental offices. They’re good at teeth. We make the “is this a fever or isn’t it” call dozens of times a week, and the honest medical answer is that a real fever points toward an infection to look for, not toward the gums.
The one rule we never bend
A timing note first, because it’s where parents get tripped up. Most babies don’t cut a first tooth until around 6 months, and it’s uncommon before 4 months. The drooling and gum-chewing that look like teething can start as early as 2 or 3 months, well before any tooth is actually on the move, so a young baby often gets labeled “teething” when teething hasn’t really begun.
Keep the rule from the top of this piece front and center: teething doesn’t cause a true fever at any age, in any baby. That’s exactly why the next line matters. Any rectal fever of 100.4°F or higher in a baby under three months old is a call-us-today situation, full stop. It gets its own rule not because a tooth might be behind it, it can’t be, but because at that age the immune system is still new to the job, and a fever can be the first and only sign of an infection that needs prompt evaluation. Don’t wait, and don’t write it off as teething, especially when the “teething” is really just early drooling. Call us, or if it’s the middle of the night, head in to be seen. For older babies you have more room to watch and comfort, but that under-three-months rule has no exceptions.
How to soothe a teething baby safely
The things that actually help are simple and cheap. Cold is your friend: a clean, chilled (not frozen) teething ring, a cold washcloth to gnaw on, or gentle pressure from a clean finger along the sore gum. If your baby is on solids, a cold food in a mesh feeder works too.
A couple of things to skip. Benzocaine numbing gels carry an FDA warning, because they’ve been linked to a rare but serious blood condition in young children, so we steer families away from them entirely for babies and toddlers. Amber teething necklaces are another no. There’s no good evidence they help, and a cord around a baby’s neck is a real strangulation and choking risk. If you’re wondering about pain or fever medicine, have that conversation with us directly, because dosing is based on your baby’s weight and we’d rather give you the right number than have you guess from a box.
When to call us
Reach out if your baby:
- Has a rectal fever of 100.4°F or higher and is under three months old (call right away, this one needs a same-day, in-person exam, not a wait-and-see or a callback)
- Has any fever of 104°F (40°C) or higher, regardless of how long it has lasted
- Has a fever of 100.4°F or higher that hangs on more than 3 days (72 hours), even if otherwise well
- Has diarrhea, vomiting, or a rash along with the fever
- Shows signs of dehydration, such as no wet diaper in eight or more hours, no tears, or a dry mouth
- Has a fever and seems genuinely unwell, unusually sleepy, hard to wake, limp, or inconsolable
- Just doesn’t seem right to you
That last one isn’t filler. You know your baby better than any chart does, and a parent’s gut is one of the better diagnostic tools we’ve got.
What we see in the office
We see this all the time. A parent brings in a baby around the time the molars arrive, certain the teeth are behind a 102 fever. The drooling and chewing are real, so the theory makes sense. But when we look closer, we often find the actual culprit elsewhere, a red, bulging eardrum being a common one. The teething is genuine. The fever is an ear infection that has nothing to do with the gums. We treat the infection, the fever breaks, and the teeth keep coming in on their own schedule. More than a few of these parents tell us afterward they almost didn’t call, because “it was probably just teething.” We’re always glad they did.
Frequently asked questions
Can teething fevers get high?
What are the worst symptoms of teething?
Why is my baby’s head hot during teething?
Is 102 a high fever for a 10-month-old?
Mike Jordan, MD, FAAP is a Board Certified pediatrician at East Lake Pediatrics, an NCQA-recognized Patient-Centered Medical Home.
East Lake Pediatrics is dedicated to promoting best practices, supporting consistency in our care, and helping ensure the best possible outcomes for the children we serve. To that end, we offer a range of educational resources, both online and as printed handouts, as part of our mission to serve our community. This material is provided for general educational purposes only. It does not constitute medical advice and is not a substitute for professional diagnosis, treatment, or the individualized guidance of your child’s physician. Always talk with your pediatrician or another qualified provider about questions regarding your child’s health, and never disregard or delay seeking care because of something you have read here. If you believe your child is experiencing a medical emergency, call 911 or go to the nearest emergency department.
