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What to do if…
your infant under three months has a fever or is unusually sleepy

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy UK guide

Short answer

Treat this as urgent. If your baby is under 3 months and has a temperature of 38°C or higher, or you think they have a fever, call NHS 111 or your GP urgently; if they will not wake up normally, are very floppy, or breathing is a struggle, call 999 or go to A&E now.

Do not do these things

  • Do not “wait it out” because the fever seems mild; babies under 3 months need urgent advice for a fever.
  • Do not rely on touch alone to decide it is safe; check a temperature if you can.
  • Do not delay 999 or A&E to take a temperature if your baby looks very unwell.
  • Do not cool them with cold baths, ice packs, or rubbing alcohol.
  • Do not overdress them or cover them in too many blankets.
  • Do not give paracetamol to a baby under 2 months unless a clinician tells you to.
  • Do not give ibuprofen to a baby under 3 months unless a doctor has prescribed it.
  • Do not give aspirin.
  • Do not drive yourself if you feel you cannot do it safely or your baby seems to be getting worse quickly; use 999.

What to do now

  1. Put your baby somewhere safe for a moment.

    • Hold them securely, or place them on a firm, flat surface.
    • Look at whether they wake, respond, breathe comfortably, and feed in their usual way.

  2. If any of these are happening, treat it as an emergency: call 999 or go to A&E now.

    • They will not wake up normally, are very floppy or limp, or are not responding in their usual way.
    • Breathing looks like hard work, including grunting, very fast breathing, long pauses, or the chest or tummy sucking in.
    • Skin, lips, or tongue look blue, grey, very pale, or blotchy, or they feel unusually cold as well as unwell.
    • They have a spotty purple or red rash that does not fade when you press the side of a clear glass against it.
    • They have a seizure or fit.
    • They are under 8 weeks old and you are very worried.

  3. Check a temperature if you can, but do not delay emergency help if they look very unwell.

    • Use a digital thermometer in the armpit.
    • Write down the number and the time you took it.
    • A temperature of 38°C or higher is a fever in this situation.

  4. If the temperature is 38°C or higher, or you think they have a fever, call NHS 111 or your GP urgently.

    • Say: “My baby is under 3 months and has a temperature of 38 or above,” or “My baby is under 3 months and I think they have a fever.”
    • Follow the advice you are given. They may tell you to go to an urgent assessment service or A&E.

  5. If the main worry is unusual sleepiness, treat that as urgent even without a confirmed temperature.

    • Call NHS 111 or your GP urgently if they are much harder to wake than usual, too sleepy to feed normally, or not themselves.
    • Use 999 or A&E if they will not wake up normally or you are seriously worried by how different they seem.

  6. While you are getting help, keep care simple.

    • Offer feeds as normal; if breastfed, offer feeds more often if they will take them.
    • Do not force feeds.
    • Do not cover them in too many clothes or blankets.
    • Keep watching breathing, colour, alertness, rash, vomiting, and wet nappies.

  7. Write down a few facts to tell the clinician.

    • Age in weeks.
    • Highest temperature and when you took it.
    • How alert they are and whether they are feeding.
    • Wet nappies today.
    • Any rash, breathing change, vomiting, or seizure.
    • Any recent vaccinations and when they happened.
    • Any medicine already given, including name, dose, and time.

  8. Be ready to leave if you are told to.

    • Take the red book if you have it nearby.
    • Take nappies, wipes, a blanket, and your notes.
    • Do not delay leaving to find non-essential items.

What can wait

  • You do not need to work out the cause right now.
  • You do not need to try cooling tricks such as sponging, cold baths, or over-undressing.
  • You do not need to decide what tests or treatment are needed.
  • You do not need to decide whether this is because of vaccinations; mention any recent vaccinations to the clinician and follow their advice.
  • Focus only on getting urgent clinical advice or emergency help.

Important reassurance

It is understandable to feel frightened when a very young baby seems hot, unusually sleepy, or different from normal. Acting quickly is the right kind of caution, and clinicians would rather assess a young baby early.

Scope note

These are first steps only: checking for emergency signs, taking a temperature if it is safe to do so, and getting the right UK help quickly. Later decisions about tests, medicines, or treatment need a clinician.

Important note

This is general information only. It is not medical, legal, financial, therapeutic, or other professional advice.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

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