When to Take a Baby with a Fever to A&E (UK)

Fever is the symptom that empties A&E waiting rooms at 2am — and also the one most parents second-guess. The NHS numbers are clearer than the folklore: 38°C is a fever, age changes how urgently you act, and how your baby looks and behaves matters as much as the thermometer.

What temperature counts as a fever in a baby?

38°C or above is a fever. A normal temperature varies slightly between children. Under 5s, the NHS prefers a digital thermometer in the armpit; forehead strips alone are not enough for decisions. If your baby has just had a bath or been tightly wrapped, wait a few minutes and recheck — but never delay escalation when red-flag behaviour is already there.

When should you call 999 or go to A&E?

Call 999, or go to A&E, if a feverish baby or child has any of these NHS immediate-action signs:

• Difficulty breathing — grunting, very fast breathing, tummy sucking in under the ribcage, or too breathless to feed
• A rash that does not fade when you press a clear glass firmly against it
• A stiff neck, or being bothered by light
• A fit / febrile seizure for the first time
• Unusually cold hands and feet
• Colour change — blue, grey, paler than usual, or blotchy skin (harder to see on brown or black skin); also check lips and tongue
• Drowsy and hard to wake, or not responding as they normally do
• Extremely agitated (will not stop crying) or confused
• Not interested in feeding or normal activities in a way that feels sharply wrong

Do not drive while your child is still seizing or unconscious — call 999. Local Healthier Together pathways also treat under 3 months + 38°C+ as needing urgent face-to-face review unless the fever is clearly within 48 hours of vaccinations and there are no other red features. If you are unsure, escalate.

When should you call NHS 111 instead of A&E?

Use 111 or your GP now for same-day advice when there are no 999 red flags but the age/temperature rules still apply — or when the illness is dragging on.

A&E is for red flags and life-threatening concern. 111 exists so babies who need same-day assessment are not left until morning. For the wider “always ill” nursery winter context, see colds, fevers and when to worry.

What can you safely manage at home?

If your child is outside the urgent age/temperature rules, has no red flags, and still has periods of being themselves between spikes, NHS advice is usually home care while the fever settles over 1–4 days.

Do
- Offer plenty of fluids; keep breastfeeding as normal
- Watch for dehydration
- Offer food if they want it — do not force
- Check regularly, including at night
- Give infant paracetamol (from 2 months) or ibuprofen (from 3 months and ≥5kg) only if they are distressed or uncomfortable

Do not
- Undress them or sponge them down to “cool” them
- Bundle them in extra layers
- Give aspirin under 16
- Alternate paracetamol and ibuprofen unless a clinician tells you to
- Give ibuprofen under 3 months, under 5kg, with chickenpox, if dehydrated, or with asthma unless a doctor has said it is OK

What if the fever is after vaccinations?

Fever in the 48 hours after routine immunisations is common. Healthier Together guidance: if your baby is otherwise well in that window, age-appropriate paracetamol can be reasonable without automatically treating it as an emergency fever visit. Still escalate if any red or amber features appear, or if you are worried — vaccination does not rule out other illness.

What should you do during a febrile seizure?

Febrile seizures usually affect children from about 6 months to 6 years, often last 2–3 minutes, and rarely last more than 10 minutes. They look terrifying; most are not dangerous long-term — but a first seizure needs medical assessment.

Call 999 / go to A&E if: first seizure; lasts over 5 minutes; breathing difficulty; stiffness/twitching on one side only; more sleepy than usual for over 1 hour afterwards; more than one seizure in 24 hours.

While waiting: note start and end time; protect the head; clear hazards; after it stops use the recovery position and check the airway is clear. Do not hold them down, put anything in their mouth, or sponge them with cold water.

What do UK parents actually say about this?

Across UK parent communities, the repeated lesson is that the hard call is rarely the number — it is trusting “not themselves” at 2am. Parents of young babies consistently say same-day 111/GP checks for under-3-month fevers felt excessive beforehand and obviously correct afterwards. Practical consensus: photograph any rash, write down the highest reading and time, and do not apologise for calling.

Who should skip the “wait and see at home” approach?

Skip home-only watching — and get urgent help — if:

• Your baby is under 3 months with a known or suspected fever (38°C+)
• Your baby is 3–6 months with 39°C+
• There is any NHS red-flag symptom above
• Medicine has not helped and they are still severely distressed, floppy, or worsening
• Your gut says this is different from their usual viral days

What we’d change about common advice online: stop ranking “how high is too high” as the main question for older babies. A hot but drinking, wet-nappied toddler with playful windows is often manageable at home with 111 backup; a mottled, grunting, hard-to-wake infant is an emergency even before the fever crosses a neat line. And teething does not cause true fever — see baby teething signs.

How do you take a baby’s temperature properly?

If you do not own one yet, a digital armpit thermometer on Amazon is the usual UK home kit (check the live price/listing).

1. Use a digital thermometer.
2. Place it in the top of the armpit.
3. Hold the arm gently against the body for the time on the leaflet (many beep).
4. Read the display.
5. Recheck if the reading conflicts with how unwell they look — and escalate on behaviour if needed.

How do you escalate a baby fever at a glance?

Condition-specific escalation (croup, bronchiolitis, tonsillitis and more) lives in our childhood illnesses hub.