That first time you feel your baby’s forehead burning up, your heart drops. I remember the panic well. A fever is one of the most common reasons parents worry — and while most fevers are the body simply fighting off an everyday infection, there are a few situations where a fever needs a doctor straight away. Let me walk you through what a fever is, what to do, and — most importantly — when to get help fast.
🚨 Read this first
A fever in a baby under 3 months (a temperature of 38°C / 100.4°F or higher) is a medical emergency — contact your doctor or go to a hospital immediately, even if your baby seems otherwise okay. In tiny babies, a fever can be the only early sign of a serious infection, so it is never a “wait and watch” situation.
What counts as a fever?
A fever is a body temperature of 38°C (100.4°F) or above. The most reliable way to check a baby is with a digital thermometer. A fever itself isn’t an illness — it’s a sign the body is fighting one, most often a common viral infection. For older babies and children, how your child is behaving matters more than the exact number on the thermometer.
What to do for an older baby’s mild fever
For a baby over 3 months who is otherwise feeding, alert and comfortable, you can usually care for a mild fever at home:
- Keep fluids up. Offer extra breast milk, formula or (for older babies) water. Staying hydrated is the single most important thing.
- Dress lightly. A light layer and a comfortable, not-too-warm room — don’t bundle your baby up, as that traps heat.
- Rest and comfort. Plenty of cuddles and calm; let your baby sleep as needed.
- Fever medicine — only if needed and correctly dosed. Infant paracetamol (and ibuprofen for babies over the age/weight your doctor advises) can help if your baby is uncomfortable. Use the exact dose for their age and weight, and check with your doctor or pharmacist first — especially for young babies.
- Keep monitoring. Check the temperature and, more importantly, how your baby is behaving.
What NOT to do
- Don’t sponge with cold water, use ice, or rub alcohol on the skin — these can be harmful and make things worse.
- Don’t over-bundle your baby in blankets or extra layers.
- Never give aspirin to a baby or child.
- Don’t guess medicine doses or combine medicines without a doctor’s guidance.
⚠️ Get medical help urgently if…
- Your baby is under 3 months with any fever (38°C/100.4°F or above).
- The fever is very high, keeps climbing, or lasts more than a few days.
- There’s a rash that doesn’t fade when you press a glass against it, a stiff neck, or sensitivity to light.
- Breathing looks fast or laboured, or your baby has a seizure/fit (call emergency services).
- Your baby is very drowsy or floppy, hard to wake, not feeding, or showing signs of dehydration (few wet nappies, no tears).
- Anything simply doesn’t feel right — trust your instinct and get them seen.
Frequently Asked Questions
What temperature is a fever in a baby?
A fever is a temperature of 38°C (100.4°F) or higher, best measured with a digital thermometer. In a baby under 3 months, any fever needs immediate medical attention.
How can I bring my baby’s fever down at home?
Keep fluids up, dress your baby lightly in a comfortable room, and offer rest and cuddles. If they’re uncomfortable, correctly dosed infant paracetamol (or ibuprofen if age-appropriate) can help — check with your doctor first. Avoid cold sponging, ice and over-bundling.
Does teething cause a fever?
No — teething may cause a very slight rise in temperature but not a true fever (38°C+). If your teething baby has a real fever, look for another cause and treat it as a fever, not teething. See my teething guide for more.
When should I worry about a baby’s fever?
Seek help urgently for any fever in a baby under 3 months, a very high or persistent fever, a non-fading rash, stiff neck, breathing trouble, a seizure, unusual drowsiness, poor feeding, or if your baby just seems very unwell.
A gentle last word
Most fevers are simply your baby’s body doing its job against a passing bug, and settle with fluids, rest and comfort. But a fever in a very young baby, or one with any of the warning signs above, is never something to wait out — when in doubt, get your baby seen. You know them best.
You might also like my guides on baby cold and cough remedies and common baby ailments and keeping your baby healthy.
This article is general information from one parent to another and is not a substitute for professional medical advice. A fever in a baby under 3 months, or any fever with warning signs, needs a doctor straight away — always consult your paediatrician.
