Baby fever: when to see a doctor?
For a baby under 3 months, any temperature of 38.0°C (100.4°F) or higher needs urgent medical attention, even at night. From 3 to 6 months, call your pediatrician at 38.0°C. For older children the threshold for a call is 39.0°C (102.2°F), and at 40.5°C (105°F) any child needs urgent help.
Fever thresholds by age
| Child’s age | Temperature | What to do |
|---|---|---|
| Under 3 months | ≥ 38.0°C / 100.4°F | See a doctor urgently, even at night |
| 3 to 6 months | ≥ 38.0°C / 100.4°F | Call your pediatrician |
| Over 6 months | 38.5 to 39.0°C / 101.3 to 102.2°F | High fever. A fever reducer can make your child more comfortable, dose as per the leaflet |
| Over 6 months | ≥ 39.0°C / 102.2°F | Call your pediatrician |
| Any age | ≥ 40.5°C / 105°F | Urgent medical help |
Why is the threshold lower for the youngest babies?
In the first 3 months, a baby’s immune system is still immature, and fever may be the only sign of a serious infection. That is why guidelines recommend urgent medical assessment even when the baby otherwise looks well.
Fever lasting more than 3 days
If a child over 6 months has had a fever for more than 72 hours, call your pediatrician, even if the child seems fairly well.
Lethargy, difficulty waking, trouble breathing, seizures or a rash that does not fade when pressed need urgent help regardless of the temperature. Full list: warning signs in babies.
Log readings with the time
The doctor will ask how long the fever has lasted, how high it was and when medicine was given. If you log readings with the time, it is easier to answer and to see whether the temperature is rising or falling.
Fever thresholds by age, when to call emergency services, the glass test and space for your pediatrician’s number. One A4 page to print. Download the cheat sheet
Calm Parent
Temperature readings with a chart, medicines given with the time and these thresholds in one place, also on the other parent’s phone. No ads, 14 days of Premium free.
Get it on Google PlaySources
- American Academy of Pediatrics, Clinical Practice Guideline: Evaluation and Management of Well-Appearing Febrile Infants 8 to 60 Days Old (2021)
- American Academy of Pediatrics, HealthyChildren.org: Fever
This article is for information only and does not replace medical advice. If something worries you, contact a doctor. In an emergency, call your local emergency number.