Fever in a well-looking child
Assess from the doorway, use the traffic light, test the urine, and give parents clear advice on when to come back.
A 2-year-old boy has had a fever of 39 °C since this morning with a runny nose. He is playful, drinking, has a normal capillary refill and pink skin. He has had 4 wet nappies today. His mother is worried the fever will "damage his brain" and wants an injection to bring it down. His grandmother has wrapped him in two blankets.
What do you check, what do you tell her, and when should she come back?
- Use the traffic lightColour, activity, breathing, circulation and hydration, other signs.
- Any red featureUrgent assessment: see the febrile child guide.
- Under 3 months with feverNot a "well child" pathway: all need assessment.
- Find the sourceEars, throat, chest, skin, urine (if no source in a young child).
- Treat distress, not the numberParacetamol or ibuprofen if uncomfortable.
- Don't alternate routinelySwitch only if still distressed before the next dose.
- Safety-net in writingReturn signs, fluids, check at night, how long fever lasts.
- Any red traffic-light feature
- Non-blanching rash
- Under 3 months
- Fever 5 days or more
- Not drinking or few wet nappies
- Fits, drowsiness, neck stiffness
| Fever | 38 °C or above |
| Paracetamol syrup | 15 mg/kg every 4–6 hours, maximum 4 doses in 24 hours |
| Ibuprofen syrup | 5–10 mg/kg every 6–8 hours, over 3 months and 5 kg, avoid in dehydration or chickenpox |
| Under 3 months with 38 °C or more | High risk |
| 3–6 months with 39 °C or more | At least amber |
| Fever 5 days or more | Think Kawasaki and other causes |
| Wet nappies | Fewer than 4 in 24 hours suggests dehydration |
Check every dose against a current drug reference and your hospital protocol.
On this page
Traffic light assessment
| Area | Green (low risk) | Amber (intermediate) | Red (high risk) |
|---|---|---|---|
| Colour | Normal | Pallor reported by parent | Pale, mottled, ashen, blue |
| Activity | Smiling, alert, normal cry | Not responding normally, reduced activity, needs prolonged stimulation | No response, can't be woken, weak or high-pitched cry |
| Breathing | Normal | Nasal flaring, fast breathing, SpO₂ 95% or less, crackles | Grunting, RR over 60, moderate or severe chest indrawing |
| Circulation and hydration | Normal skin and eyes, moist mouth | Dry mouth, poor feeding, CRT 3 seconds or more, reduced urine | Reduced skin turgor |
| Other | None of amber or red | Fever 5 days or more, rigors, swelling of a limb or joint, age 3–6 months with 39 °C or more | Age under 3 months with 38 °C or more, non-blanching rash, bulging fontanelle, neck stiffness, fits, focal signs |
Decision
- Home with advice
- treat distress
- safety-net
- Senior review
- consider urine, bloods, chest X-ray
- safety-net with a clear plan or admit
- Urgent assessment and treatment
- see the febrile child guide
Find the source
- Ears: red bulging drum.
- Throat: tonsils, ulcers.
- Chest: fast breathing, crackles.
- Skin: rash, cellulitis, chickenpox.
- Joints and bones: swelling, not using a limb.
- Urine: clean-catch sample if no source, especially in under 3s and with amber features.
- Season and place: dengue, malaria, typhoid testing when appropriate.
Myths about fever
- Fever doesn't damage the brain. It is the body's response to infection.
- Febrile fits are frightening but usually harmless, and paracetamol or ibuprofen don't prevent them.
- How high the fever is doesn't tell you how serious the illness is. How the child looks does.
- Tepid sponging, cold baths and wrapping up are not recommended. Dress the child normally.
- Injections to bring down fever aren't needed when the child can drink and take syrup.
Treatment
Check the strength of the syrup (for example 120 mg/5 mL or 250 mg/5 mL paracetamol) and show the parent the right volume. Dosing errors are common.
Safety-net advice (write it down)
Come back immediately if the child:
- Has a rash that doesn't fade under a glass.
- Is hard to wake, floppy, or has a weak or high-pitched cry.
- Has fast breathing, grunting, or the chest sucking in.
- Has a fit.
- Isn't drinking, or has fewer than 4 wet nappies in 24 hours.
- Has fever for 5 days or more.
- Is getting worse, or the parent is worried.
Common mistakes
- Treating the number instead of the child.
- Giving an injection for fever in a child who can drink.
- Not checking urine in a young child with no source.
- Dosing by age instead of weight.
- Forgetting the under-3-month rule.
- No written safety-net.
Frequently asked questions
What is the paracetamol dose for a child?
15 mg/kg every 4–6 hours, up to 4 doses in 24 hours. Calculate from the child's weight and check the syrup strength.
Does fever cause brain damage?
No. Fever is the body's response to infection. Treat the child's distress, not the number.
Should I alternate paracetamol and ibuprofen?
Not routinely. Use one; switch only if the child is still distressed before the next dose is due.
When should a child with fever be seen urgently?
With a non-blanching rash, drowsiness, fast breathing or grunting, poor drinking, a fit, age under 3 months, or fever lasting 5 days or more.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
1. What is the paracetamol dose for a child with fever?
Answer: 15 mg/kg every 4–6 hours. Maximum 4 doses in 24 hours, by weight.
- 1 g for all ages: Adult dose.
- 5 mg/kg once a day: Too low.
- 30 mg/kg every 2 hours: Overdose.
- 50 mg/kg every 4 hours: Overdose.
2. A playful 2-year-old has a fever of 39 °C and a runny nose. What is the most important assessment?
Answer: How the child looks. Use a traffic-light assessment of colour, activity, breathing and circulation.
- The exact temperature: Height doesn't predict serious illness.
- Blood culture: Not needed.
- Chest X-ray: Not needed.
- CRP in all: Not needed if well.
3. A mother asks if paracetamol prevents febrile fits. What is correct?
Answer: No. Treat distress, not the number; febrile fits are usually harmless.
- Yes, if combined with sponging: No.
- Only ibuprofen does: No.
- Yes, always: Not true.
- Only if given every 2 hours: No.
4. A 3-year-old (14 kg) drank an unknown amount of paracetamol syrup 2 hours ago. Possible ingestion is 2 g. What is the next step?
Answer: Paracetamol level at 4 hours. Estimate the ingested dose: 2 g/14 kg ≈ 143 mg/kg — potentially toxic (> 150 mg/kg; some use 75 mg/kg for high-risk). Measure the paracetamol level at 4 hours post-ingestion and treat with acetylcysteine if above the nomogram line; start immediately if presenting > 8 h with significant ingestion. Activated charcoal within 1 hour. Prevent with child-resistant containers and safe storage.
- Discharge — syrups are safe: A toxic dose is possible (over 140 mg/kg).
- Induce vomiting: Inducing vomiting is not recommended.
- Start N-acetylcysteine only if jaundiced: Waiting for jaundice is far too late.
5. A 9-year-old has fever, migratory polyarthritis of large joints and a new apical pansystolic murmur 3 weeks after a sore throat. ASO titre is high. What long-term treatment is essential?
Answer: Benzathine penicillin 3–4 weekly. Acute rheumatic fever (Jones criteria) with carditis: treat with penicillin (eradicate strep), aspirin/NSAIDs for arthritis, and heart failure management. The key is secondary prophylaxis with IM benzathine penicillin every 3–4 weeks — with carditis for at least 10 years or until age 21–40 depending on severity — to prevent recurrences that worsen rheumatic heart disease (mitral regurgitation/stenosis).
- One 10-day course of amoxicillin: One course of amoxicillin treats the throat but does not prevent recurrence; long-term prophylaxis is needed.
- Long-term NSAIDs: NSAIDs relieve arthritis but do not prevent recurrent streptococcal infection.
- Oral penicillin for 1 year only: One year is too short; with carditis prophylaxis continues for years.
6. Which part of the brain directly controls autonomic reflexes and body temperature?
Answer: Hypothalamus. The hypothalamus integrates autonomic control: temperature, hunger, thirst, water balance (ADH), circadian rhythms and pituitary function. It acts through brainstem autonomic centres and the pituitary.
- Thalamus: A sensory relay station.
- Cerebral cortex: Higher functions; it can influence but does not directly control autonomic reflexes.
- Cerebellum: Coordinates movement.
- Basal ganglia: Control movement initiation.
7. A young woman took a large paracetamol overdose 6 hours ago, and her paracetamol level is above the treatment line. Which antidote should be given?
Answer: N-acetylcysteine. In overdose, excess paracetamol is converted by CYP450 to NAPQI, a toxic metabolite normally neutralised by glutathione. When glutathione runs out, NAPQI damages hepatocytes (centrilobular necrosis). N-acetylcysteine restores glutathione and is most effective within 8 hours, but helps at any time.
- Naloxone: Opioid antidote.
- Flumazenil: Benzodiazepine antidote.
- Atropine: Organophosphate antidote.
- Phytomenadione: Warfarin reversal; does not treat the cause.
References and dose sources
- NICE NG143 — Fever in under 5s
- Paracetamol dosing: Drugs.com: Acetaminophen (paracetamol) dosage (see also our paracetamol dose page)
- Ibuprofen dosing: Drugs.com: Ibuprofen dosage (see also our ibuprofen dose page)
International guidance is linked where it reflects good practice. Where your hospital’s protocol differs, follow your hospital.