Fever With Teething: How High Is Too High?

A temperature above 38.0°C (100.4°F) is too high to blame on teething. Multiple prospective studies tracking infants through tooth eruption have found that teething produces, at most, a barely measurable rise in body temperature that stays well below the clinical threshold for fever. If your baby has a genuine fever while cutting a tooth, something else is going on, and that something else deserves attention rather than being dismissed as a teething symptom.

What the Studies Actually Measured

The belief that teething causes fever is deeply held, but the thermometer tells a different story. A clinical trial that tracked infants through eruption of their primary teeth found that body temperature rose slightly only on the actual day a tooth broke through the gum, reaching an average of 36.70°C. That was significantly different from the day before and the day after eruption, but it is nowhere near fever territory.¹ Another prospective study that followed children longitudinally confirmed a temperature bump on eruption day, with maximum readings of 36.8°C by ear thermometer and 36.6°C under the arm.² To put that in context, those readings are within completely normal range for a healthy infant.

A separate cohort study compared temperatures on days when a tooth was actively erupting (“toothdays”) to days when no tooth was coming through. The result was essentially a tie: 36.21°C versus 36.18°C. The researchers found no statistically significant link between tooth eruption and either high or low fever.³ And a prospective study published in Pediatrics that tracked symptoms during teething found that fever above 102°F (38.9°C) was not significantly associated with tooth emergence at all. No child in the study spiked a temperature of 104°F.⁴

A systematic review and meta-analysis that pooled results from multiple studies came to a nuanced conclusion. Overall, there was no significant association between fever and primary tooth eruption. However, in a subgroup analysis restricted to studies that used rectal temperature measurement, a modest association did emerge.⁵ That finding hints at a possible small, real temperature increase with teething, but one that is clinically trivial. The pattern across studies is consistent: teething may warm your baby up a fraction of a degree, but it does not produce what any pediatrician would call a fever.

Where the Fever Line Actually Is

For infants and young children, fever is generally defined as a rectal temperature of 38.0°C (100.4°F) or above. A study of nearly 700 healthy infants under three months old established this threshold by measuring rectal temperatures during well-baby visits. The mean was 37.5°C, and values at or above 38.0°C fell above the 95th percentile.⁶ That 38.0°C cutoff is the one most widely used in clinical practice today.

The teething-related temperature bumps described in the studies above peak around 36.7–36.8°C, which is roughly a full degree Celsius below the fever threshold. That gap matters. Parents sometimes describe their baby as feeling “warm” during teething and round that sensation up to “fever.” A warm forehead can genuinely reflect a small temperature increase caused by local inflammation around the erupting tooth, but feeling warm and having a fever are not the same thing. If you take an actual reading and it sits below 38.0°C, what you are seeing is consistent with teething. If it is above 38.0°C, teething is not a sufficient explanation.

Why Parents and Even Some Doctors Get This Wrong

Despite the clinical evidence, the belief that teething causes fever is remarkably persistent. In a survey of Australian parents, 70 to 85 percent believed that teething causes fever, along with pain, irritability, drooling, and sleep disturbance.⁷ A study in Nigeria found that about 42 percent of mothers specifically expected fever to accompany tooth eruption.⁸ And it is not just parents. A survey of parents, nurses, and physicians together found that 76 percent of all respondents believed tooth eruption was associated with infant illness. Nurses and parents were the most convinced; physicians were somewhat more skeptical, but a substantial number still attributed potentially serious symptoms to teething.⁹

These beliefs are not random. They reflect what parents see with their own eyes: a baby who is drooling, fussy, and warm, with a tooth visibly pushing through the gum. The problem is that the human brain is a pattern-matching machine, and it matches these events even when the connection is coincidental. In the cohort study that compared toothdays to non-toothdays, all parents retrospectively reported that their children had suffered a range of teething symptoms, even though objective daily records kept by staff showed almost no association between tooth eruption and those symptoms.³ Memory rewrites the story to fit the narrative we expect.

The Real Reason Babies Get Sick While Teething

The timing of teething creates a near-perfect setup for coincidence. Most babies start cutting teeth between about six and twelve months of age. This is exactly the period when the passive immunity they received from their mother during pregnancy and through early breastfeeding begins to fade. At the same time, babies at this age are putting everything in their mouths, crawling on floors, and generally encountering pathogens for the first time.¹⁰ The result is that common childhood infections, which often come with real fevers, cluster in the same months that teeth happen to be arriving.

Acute respiratory viral infections in particular tend to coincide with teething periods in young children, creating a muddled clinical picture that makes it harder to distinguish what is teething discomfort and what is genuine illness.¹¹ When a baby has a stuffy nose, a fever, and a tooth coming in, parents understandably blame the tooth. But the fever is far more likely coming from whatever virus the baby picked up at daycare last week.

When You Should Call the Doctor

The practical question most parents have is simple: at what point do I stop assuming it is “just teething” and seek medical attention? The answer depends partly on the baby’s age and partly on how high the temperature goes.

For very young infants under 28 days old, any fever is treated urgently. Clinical practice guidelines recommend that all febrile newborns in this age group be evaluated aggressively, often with hospitalization and antibiotics while tests are processed.¹² Most babies this young have not started teething, so the scenario is uncommon, but it is worth knowing: in a newborn, there is no fever low enough to shrug off. Data on how these young infants are managed in practice show that those under one month are significantly more likely than older infants to receive blood cultures, lumbar punctures, and antibiotics at first evaluation.¹³

For babies in the typical teething window of roughly six to thirty months, a good rule of thumb is:

Below 38.0°C (100.4°F): Not a fever. Consistent with teething-related warmth or normal daily variation. No medical action needed for the temperature itself.
38.0°C to 39.0°C (100.4°F to 102.2°F): A real but low-grade fever. Teething alone does not explain this. Watch for other signs of illness such as congestion, vomiting, poor feeding, or unusual lethargy. Contact your pediatrician if symptoms persist beyond a day or the baby seems unwell.
Above 39.0°C (102.2°F): A moderate to high fever that warrants a call to the doctor promptly. This temperature range was flagged in pediatric practice guidelines as a threshold for further evaluation in young children with no obvious source of infection.¹²

Any fever accompanied by a rash that does not blanch when pressed, stiff neck, persistent vomiting, difficulty breathing, or unusual listlessness calls for immediate medical attention regardless of the number on the thermometer.

The Real Cost of Blaming Teething

This is not an abstract debate. When parents attribute a fever to teething, they sometimes delay seeking care for infections that need treatment. Researchers have directly flagged this risk: false beliefs about teething symptoms can interfere with the prompt diagnosis and management of serious childhood illnesses.¹⁰ A study from southeast Iran made a similar point, noting that misconceptions about teething symptoms present real risks to infants when they lead parents to delay or forgo medical evaluation.¹⁴

The prospective study from Pediatrics that found no teething child had a temperature of 104°F made the point implicitly: if your baby’s temperature gets that high, teething is not what you are dealing with.⁴ A urinary tract infection, ear infection, or viral illness is a far more likely cause, and each one benefits from timely recognition. Calling the pediatrician does not mean you are overreacting. It means you are not letting a cultural assumption make the decision for you.

What Actually Helps a Teething Baby

If the fever part of the equation turns out to be a non-issue, parents still want to know what to do about the genuine discomfort of teething. The evidence here is thinner than you might expect, but a few things are well established.

Chilled (not frozen) teething rings and clean, cool washcloths for the baby to gnaw on provide counter-pressure on the gums that many infants find soothing. Gentle gum massage with a clean finger works on a similar principle. These are the mainstays of non-pharmacological teething relief, and they carry no safety concerns.

What you should avoid is more clearly defined. In 2011, the U.S. Food and Drug Administration warned against the use of any benzocaine-containing products for infant teething because of the risk of methemoglobinemia, a condition where the blood’s ability to carry oxygen is impaired.¹⁵ Lidocaine-based teething gels have their own problems. Case reports have linked them to seizures, respiratory arrest, and death in infants and young children. Both the American Academy of Pediatrics and the Australian and New Zealand Society of Paediatric Dentistry recommend against topical agents for teething, and the FDA specifically advises against topical lidocaine for this purpose.¹⁶

If your baby seems to be in enough pain that chilled teething rings are not cutting it, a weight-appropriate dose of acetaminophen (for babies old enough per your pediatrician’s guidance) is generally considered safe and more effective than topical products. Ask your doctor about dosing rather than relying on packaging, because infant formulations can vary.

Teething Myths Have a Long History

The idea that teething is dangerous has deep roots. Ancient medical texts, including those attributed to Hippocrates, listed teething as a source of fever, swelling, and colic. By the 17th and 18th centuries in Europe, teething was formally recorded as a cause of death on mortality registers.¹⁷ Lancing the gums with sharp instruments was a standard medical treatment for centuries, and various teething powders containing mercury or lead compounds were sold well into the early 20th century.

Modern medicine has firmly dismissed the idea that teething is life-threatening, but the cultural residue of those centuries of belief is still visible in how parents talk about teething today. Surveys across multiple countries and cultures continue to find remarkably similar patterns of belief, though the specific folk practices vary. In some communities, herbal remedies are rubbed on the gums; in others, amulets are used. The common thread is a conviction that tooth eruption is a medically significant event that requires intervention.¹⁸ The research suggests that the intensity of these beliefs varies with cultural context and oral health literacy but shows up to some degree almost everywhere.¹⁹

Understanding this history is useful not because it changes the medical advice, but because it explains why the “teething causes fever” belief is so resistant to correction. It is not a modern misunderstanding. It is a very old idea, reinforced across centuries and cultures, that happens to align with a coincidence of timing. Breaking that cycle takes more than a single conversation with a pediatrician; it takes a shift in what gets passed down between generations of parents.

1
PubMed Central. Signs and symptoms associated with primary tooth eruption: a clinical trial of nonpharmacological remedies
2
Pediatrics. Prospective Longitudinal Study of Signs and Symptoms Associated With Primary Tooth Eruption
3
Pediatrics. Teething and Tooth Eruption in Infants: A Cohort Study
4
PubMed. Symptoms associated with infant teething: a prospective study
5
PubMed Central. Association between Fever and Primary Tooth Eruption: A Systematic Review and Meta-analysis
6
PubMed. What is fever? Normal temperature in infants less than 3 months old
7
PubMed. Parent beliefs about infant teething: a survey of Australian parents
8
The Journal of Contemporary Dental Practice. Teething Problems and Parental Beliefs in Nigeria
9
PubMed. Parents’ and medical personnel’s beliefs about infant teething
10
PubMed. Teething: myths and facts
11
DRUGS AND RATIONAL PHARMACOTHERAPY. A Comprehensive Approach to Treating Acute Respiratory Viral Infections in Young Children Experiencing Teething
12
PubMed. Practice guideline for the management of infants and children 0 to 36 months of age with fever without source
13
JAMA. Management and Outcomes of Care of Fever in Early Infancy
14
Academia.edu / Journal of Comprehensive Pediatrics. Infants Teething Problems and Mothers’ Beliefs in South East of Iran
15
PubMed. What are pharmacists recommending for infant teething treatment?
16
PubMed. Are teething gels safe or even necessary for our children? A review of the safety, efficacy and use of topical lidocaine teething gels
17
Kaleidoscope History. History of Misconceptions Surrounding Teething
18
PubMed Central. Mothers’ false beliefs and myths associated with teething
19
PubMed Central. Misconceptions and traditional practices towards infant teething symptoms among mothers in Southwest Ethiopia