Fever in Children
A raised temperature in a child, usually from a self-limiting viral infection.
Last revised
Key takeaways
- Defined as: 38C or above
- Under 3 months with 38C or above: urgent assessment required
- Most useful single change: Keep fluids going; this matters more than the temperature.
- Commonest mistake: Aspirin in under-16s.
- See a doctor if any of the signs under "When to get help" below apply to you.
Why it matters
How the child looks and behaves matters far more than the number on the thermometer.
The numbers, in one place
| Measure | Figure |
|---|---|
| Defined as | 38C or above |
| Under 3 months with 38C or above | urgent assessment required |
| Treat for | discomfort, not to normalise the reading |
| Never give aspirin | to anyone under 16 |
| Traffic light system | used by clinicians to assess risk |
What helps
- Keep fluids going; this matters more than the temperature
- Give paracetamol or ibuprofen for distress, not for the number
- Dress lightly rather than wrapping up or sponging with cold water
- Check on them regularly, including overnight
What to avoid
- Aspirin in under-16s
- Routinely alternating paracetamol and ibuprofen without advice
- Judging severity by the thermometer alone
Where to go next
- What People Get Wrong About Fever in Children
- Fever in Children: A Beginner-Friendly Start
- Childhood Nutrition: Sorting the Evidence From the Noise
- Children and Screens: Sorting the Evidence From the Noise
When to get help
Call 999 for a rash that does not fade under pressure, a stiff neck, a seizure, difficulty breathing, blue or mottled skin, a weak or high-pitched cry, or a child who is floppy, will not wake or is unusually drowsy. Any fever of 38C or above in a baby under three months needs urgent assessment. Trust your instinct if a child seems seriously unwell.
Where this comes from
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.