When to see a healthcare provider for fever depends on a person’s age, whether they have other concerning symptoms, and how long the fever lasts. For infants under 3 months, any fever of 100.4°F or higher is serious and requires immediate medical attention. For children between 3 to 12 months, a fever over 102°F also needs a healthcare provider’s evaluation.
When to See a Healthcare Provider for Fever
Fever is defined as a core temperature higher than 100.4°F (38°C).Alow-grade feveris a core temperature between 99.6°F and 100.3°F.
In adults, a low-grade fever isn’t usually concerning unless it comes and goes. But in babies, any fever at all can signal a serious problem.
Infants and Children
For young children (3 to 12 months), call a provider if the fever is higher than 102°F or lasts longer than 24 hours.For children older than 12 months, call a provider if the fever reaches 103°F or higher.
Other reasons to call a doctor or seek medical care for your child include:
Call 911 immediately or go to the nearest emergency room if any of the following occur:
Fever in Adults
For adults, call a doctor if you have any of the following symptoms:
Seek emergency care if any of the following occur with your fever:
If you are receiving chemotherapy and your fever lasts more than one hour, seek emergency medical care.
Fevers Aren’t Harmful in ThemselvesAlthough people worry about fever, it’s only a symptom of an illness, not an illness itself.A fever is the body’s way of fighting off an infection and is almost never harmful.
Fevers Aren’t Harmful in Themselves
Although people worry about fever, it’s only a symptom of an illness, not an illness itself.A fever is the body’s way of fighting off an infection and is almost never harmful.
Best Ways to Take a Temperature
There are five ways to take a person’sinternal temperature, listed below from most accurate to least:
For babies and toddlers up to 3 years of age, it is especially important to take the child’s temperature using the rectal method. The oral and tympanic methods are both accurate, but only when done properly.
Summary
In newborns (birth to 3 months), a temperature higher than 100°F warrants emergency medical care. An infant’s temperature should be taken with a rectal thermometer. If you are an adult with a fever of 104°F or higher, you should also seek medical care.
While a fever itself is not harmful, it can be a sign of a serious medical condition. Call your healthcare provider or seek medical care if you are experiencing any other concerning symptoms, or if you have another serious health condition like cancer or diabetes.
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Stamford Health.Fevers in adults, children, and toddlers: When to worry.Harvard Health Publishing.Fever in adults: When to worry.Johns Hopkins.Fever.Seattle Children’s.Fever (0-12 months).Nemours Children’s Health.Fevers.Evans SS, Repasky EA, Fisher DT.Fever and the thermal regulation of immunity: the immune system feels the heat.Nat Rev Immunol.2015;15(6):335-49. doi:10.1038/nri3843Seattle Children’s.Fever - how to take a temperature.Additional ReadingAmerican Academy of Family Physicians.Fever in infants and children.Mayo Clinic.Fever: Symptoms and causes.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Stamford Health.Fevers in adults, children, and toddlers: When to worry.Harvard Health Publishing.Fever in adults: When to worry.Johns Hopkins.Fever.Seattle Children’s.Fever (0-12 months).Nemours Children’s Health.Fevers.Evans SS, Repasky EA, Fisher DT.Fever and the thermal regulation of immunity: the immune system feels the heat.Nat Rev Immunol.2015;15(6):335-49. doi:10.1038/nri3843Seattle Children’s.Fever - how to take a temperature.Additional ReadingAmerican Academy of Family Physicians.Fever in infants and children.Mayo Clinic.Fever: Symptoms and causes.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Stamford Health.Fevers in adults, children, and toddlers: When to worry.Harvard Health Publishing.Fever in adults: When to worry.Johns Hopkins.Fever.Seattle Children’s.Fever (0-12 months).Nemours Children’s Health.Fevers.Evans SS, Repasky EA, Fisher DT.Fever and the thermal regulation of immunity: the immune system feels the heat.Nat Rev Immunol.2015;15(6):335-49. doi:10.1038/nri3843Seattle Children’s.Fever - how to take a temperature.
Stamford Health.Fevers in adults, children, and toddlers: When to worry.
Harvard Health Publishing.Fever in adults: When to worry.
Johns Hopkins.Fever.
Seattle Children’s.Fever (0-12 months).
Nemours Children’s Health.Fevers.
Evans SS, Repasky EA, Fisher DT.Fever and the thermal regulation of immunity: the immune system feels the heat.Nat Rev Immunol.2015;15(6):335-49. doi:10.1038/nri3843
Seattle Children’s.Fever - how to take a temperature.
American Academy of Family Physicians.Fever in infants and children.Mayo Clinic.Fever: Symptoms and causes.
American Academy of Family Physicians.Fever in infants and children.
Mayo Clinic.Fever: Symptoms and causes.
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