Teething can raise your baby’s body temperature slightly, but it does not cause a true fever. The distinction matters: a true fever is 100.4°F (38°C) or higher, while teething typically keeps temperatures below that line. If your baby feels warm while a new tooth is pushing through, there’s a real biological reason for it, but any temperature at or above 100.4°F points to something else going on.
What Happens Inside the Gums
When a tooth pushes through gum tissue, it creates a small zone of trauma. The body responds the same way it does to any tissue injury: it sends inflammatory molecules to the site. Researchers have measured these molecules, specifically in the fluid around erupting teeth, and found significantly elevated levels of the same compounds the immune system uses to fight infections.
These inflammatory compounds don’t stay local. Small amounts enter the bloodstream and reach the brain’s temperature-control center, which sits in the hypothalamus. There, they trigger a chain reaction that nudges the body’s thermostat upward. Blood vessels near the skin constrict to hold heat in, and the body generates a bit more metabolic warmth. The result is a mild temperature bump, often just a fraction of a degree above normal.
This is the same basic pathway the body uses during an infection, just at a much smaller scale. A single tooth breaking through a thin layer of gum tissue produces far less inflammation than, say, a virus replicating across the respiratory tract. That’s why teething warmth stays subtle while an actual illness can push temperatures well above 101°F.
How Warm Is Normal During Teething
Normal body temperature sits around 98.6°F (37°C), though it fluctuates throughout the day. During teething, your baby’s temperature might rise into the 99 to 100°F range. Once it reaches 100.4°F or higher, it meets the medical definition of a fever, and teething alone doesn’t push temperatures that high.
The American Academy of Pediatrics draws the line at 101°F (38.3°C): if your baby’s temperature hits that mark, teething is not the cause. That said, some pediatric sources use the stricter 100.4°F cutoff. Either way, the message is the same. A genuinely feverish baby has an infection, not a teething problem, even if a tooth happens to be coming in at the same time.
Why the Timing Fools So Many Parents
Babies start teething around 4 to 7 months old, which is exactly when the passive immunity they received in the womb begins to fade. They’re also putting everything in their mouths, exposing themselves to new germs constantly. The overlap means infections and tooth eruptions frequently happen at the same time, making it easy to blame the tooth for symptoms that actually come from a virus.
Studies reflect this confusion. In one survey, nearly 50% of parents reported fever as a teething symptom, and about 35% reported teething pain. But when researchers tracked babies closely in a controlled study of 46 infants, they found that temperature spikes clustered tightly around the day of eruption: 20 out of 46 babies had a temperature above 99.5°F on eruption day, compared to seven or fewer on any given day in the weeks before. The spike was real but brief and mild.
Symptoms Teething Actually Causes
Genuine teething symptoms are modest and short-lived. You can expect:
- Mild irritability that comes and goes, especially in the day or two before the tooth breaks through
- Excessive drooling, which can start weeks before a tooth appears
- A desire to chew on hard objects, fingers, or anything within reach
- Slightly warm skin, with a temperature that stays below the fever threshold
- Swollen or tender gums at the site where the tooth is emerging
Teething does not cause significant diarrhea, a runny nose, a cough, rash, or prolonged inconsolable crying. If your baby has any of those symptoms alongside warmth, an illness is the more likely explanation.
When Warmth Signals Something Else
Because teething overlaps with the age when babies catch their first colds, ear infections, and stomach bugs, it’s important to know what doesn’t belong. A temperature of 100.4°F or higher is the clearest sign that an infection, not a tooth, is responsible. Other red flags include diarrhea lasting more than two loose stools, a rash that spreads beyond the chin and cheeks (drool rash is common and harmless), unusual sleepiness or difficulty waking, and refusal to drink fluids.
Babies under 3 months old with any fever need prompt medical attention regardless of whether teething seems like a possibility, because serious infections at that age can be hard to spot from symptoms alone.
Helping Your Baby Feel Better
For the mild discomfort teething actually produces, simple measures work well. A chilled (not frozen) teething ring or a clean, cold washcloth gives your baby something safe to gnaw on and provides gentle pressure against sore gums. Rubbing the gums with a clean finger can also help. Keep a bib handy to manage the extra drool, since wet skin on the chin and neck can become irritated.
If your baby seems genuinely uncomfortable and non-medication approaches aren’t enough, infant acetaminophen is an option for babies 3 months and older, dosed by weight and given no more than every 4 to 6 hours. Infant ibuprofen is available for babies 6 months and older, dosed by weight every 6 to 8 hours. Always use the syringe or measuring device that comes with the bottle rather than a kitchen spoon, and follow the weight-based instructions on the packaging.
Avoid numbing gels containing benzocaine for children under 2, and skip teething tablets or jewelry, which carry choking and toxicity risks that outweigh any benefit. The discomfort from a single erupting tooth typically lasts only a few days, so your baby won’t need ongoing relief for weeks at a time.