Guide
Fever in baby
Babies often develop fevers, and in most cases it isn't a sign of something serious.
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Are fevers normal?
A fever is usually a sign your baby's body is doing its job — fighting off an infection. Most fevers in babies over 3 months are mild and pass within a few days. How your baby is acting matters more than the number on the thermometer.
Why this happens
A fever is the body's natural response to infection — usually a common virus. Raising body temperature helps the immune system to work more effectively to clear the bug.
What you might see
- A temperature of 38°C or above
- Flushed cheeks, warm forehead or back
- Slightly less energy or feeding a bit less
- Mild fussiness or wanting extra cuddles
At a glance — tap to jump
Red flag
Get medical help urgently if
- Under 3 months old with a temperature of 38°C or higher
- 3–6 months old with a temperature of 39°C or higher
- A rash that doesn't fade when you press a glass against it
- Difficulty breathing, blue lips, or grunting with each breath
- Floppy, unresponsive, or very hard to wake
- A fit (seizure) for the first time
Watch
Watch more closely if
- Temperature stays above 39°C for more than 24 hours
- Baby is unusually sleepy or irritable
- Feeding noticeably less than usual
- Symptoms haven't improved after 3 days
Normal
Usually safe if
- Baby is over 3 months old
- Still alert, making eye contact, smiling between cuddles
- Having wet nappies as usual (at least 6 in 24h)
- Settling with paracetamol or ibuprofen (if age appropriate)
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In an emergency, always call 999. For advice at any time, call NHS 111 or your GP. LittleNest is here to help you decide — it isn't a diagnosis.