what temp is a fever for a baby
A fever in a baby is generally a temperature of 38°C (100.4°F) or higher , but the age of the baby and how you measure the temperature really matter.
Quick Scoop
- For most babies, a fever = 38°C (100.4°F) or higher when measured rectally (in the bottom) or on the forehead.
- Under the arm (armpit), 99°F (37.2°C) or higher can count as a fever, but this method is less accurate.
- Normal baby temperature is around 36.4°C (97.5–99.5°F) , with small ups and downs during the day.
By Age: When to Worry
- Newborns under 3 months :
- Any temperature 38°C (100.4°F) or higher (rectal or forehead) is an emergency – call your doctor or seek urgent care right away.
- 3–12 months :
- Fever is still 38°C (100.4°F) or higher , but how worried to be depends on how the baby looks (alert vs. floppy, drinking vs. not drinking, etc.).
Quick temperature guide (method vs fever)
| How you measure | Fever level |
|---|---|
| Rectal (bottom) | ≥ 38.0°C (100.4°F) | [1][5][7][9]
| Forehead (temporal) | ≈ 38.0°C (100.4°F) or higher | [7][9][1]
| Armpit (axillary) | ≥ 37.2°C (99°F) | [5][9][1][7]
When to call a doctor now
Call your pediatrician or emergency services urgently if:
- Baby is under 3 months and has 38°C (100.4°F) or higher.
- Baby is very sleepy, hard to wake, floppy, or not responding normally.
- Baby has trouble breathing, bluish lips/face, or fast breathing.
- Baby has fewer wet diapers , not drinking, or shows signs of dehydration (very dry mouth, no tears).
- Fever lasts more than 24 hours in a baby under 2 years, or you’re just really worried.
Simple at‑home steps (if baby otherwise seems okay)
If your baby is older than 3 months, breathing comfortably, and still drinking:
- Offer plenty of fluids (breastmilk/formula).
- Dress in light clothing , not heavy blankets.
- Keep the room cool and comfortable.
- Fever medicines (paracetamol/acetaminophen, sometimes ibuprofen if age‑appropriate) should only be given using correct dosing and after checking with your doctor.
If your baby feels very hot or “not themselves,” it’s always safest to call your pediatrician, even if the number on the thermometer is borderline.
Bottom note: Information gathered from public forums or data available on the internet and portrayed here.