Fever in Children: Recognising the Seriously Ill Child
How to use the NICE NG143 traffic light system to distinguish a self-limiting viral illness from a potentially life-threatening infection in a febrile child, and when to call 999, refer urgently, or safely advise home care.
Why this matters
Most fevers in children under five years are caused by self-limiting viral infections that resolve without treatment. A small but significant minority represent serious bacterial illness, including meningococcal disease, bacterial meningitis, pneumonia, sepsis, or urinary tract infection. The challenge for a community pharmacist is that both presentations can look similar in the early stages, and the window for safe intervention in the serious cases is narrow.
NICE guideline NG143 provides a structured traffic light system covering red, amber, and green features that community pharmacists can apply to a history taken at the counter or by phone.1 Community pharmacists are explicitly acknowledged in the guideline as practitioners who may not be able to complete the full clinical assessment.
Several assumptions commonly made by parents and carers are clinically incorrect, and correcting them is part of the pharmacist\'s role. Antipyretic medicines do not prevent febrile convulsions, so giving paracetamol to ward off a fit is not a reason to use it. The response to paracetamol or ibuprofen tells you nothing about severity: a child with serious bacterial infection may feel and look better an hour after a dose.1 Aspirin must never be given to children under 16 years because of the risk of Reye\'s syndrome, a rare but potentially fatal condition causing liver and brain damage.5
Age is the single most important variable at the outset. An infant under three months with a temperature of 38 degrees Celsius or above is in the highest risk group regardless of how well they appear. NICE NG143 is unambiguous: reported parental concern about a fever is a valid clinical signal and should not be dismissed.
Red flags vs more likely benign
| Feature | More likely benign | Red flag ⚠ |
|---|---|---|
| Age and temperature | Over 6 months with mild fever; 3 to 6 months with temperature below 39°C; child appears well | Under 3 months with any temperature of 38°C or above: high-risk regardless of appearance (NICE NG143)1 |
| Skin colour | Normal pink colour in skin, lips, and tongue | Pale, mottled, ashen, or blue-tinged skin, lips, or tongue |
| Rash | No rash; or a blanching rash that disappears completely when pressed with a glass tumbler | Non-blanching rash: rash remains visible under glass pressure; treat as possible meningococcal disease and call 999 |
| Alertness | Responds to parent, smiles or shows social awareness, stays awake, wakes easily | No response to social cues, cannot be roused or will not stay awake, appears ill to an observer |
| Cry | Strong normal cry, or quiet and settled without distress | Weak, high-pitched, continuous, or inconsolable cry |
| Breathing | No reported difficulty; normal effort with no added noise | Grunting; reported rapid or laboured breathing; moderate or severe chest indrawing |
| Fontanelle (infants) | Flat or slightly sunken (very sunken may indicate dehydration) | Bulging fontanelle: possible raised intracranial pressure |
| Neck | Moves neck freely in all directions | Neck stiffness or resistance to moving chin towards chest: possible bacterial meningitis |
| Seizure | No seizure; previous simple febrile convulsion in an otherwise well child is lower risk | Active seizure lasting more than 5 minutes (convulsive status epilepticus) |
Assessing a febrile child at the pharmacy counter
A community pharmacist may not be able to complete the full NICE clinical assessment, particularly heart rate, respiratory rate, capillary refill time, oxygen saturation, and physical examination. If concerning features are reported, observed, or cannot be confidently assessed, escalation is safer than reassurance.
- Parental concern is a valid clinical signal. NICE NG143 recommendation 1.1.6 states that reported parental concern about a fever should be taken seriously. A parent who says "they're just not right" or "I've never seen them like this before" should be taken seriously and should lower the threshold for same-day clinical assessment, even if the formal traffic light features are not yet clear. A parent who has sought advice repeatedly about the same illness warrants a lower threshold for referral.
- Temperature alone above six months does not predict severity. NICE NG143 is clear: in children older than six months, temperature alone should not be used to identify those with serious illness.1 A child with an otherwise reassuring appearance may still have a self-limiting viral infection even with a high temperature, while a child with a lower temperature but abnormal appearance and behaviour may have a serious illness. Appearance and responsiveness matter far more than the number on the thermometer.
- Do not use temperature response to antipyretics as reassurance. A febrile child who feels better an hour after paracetamol has not been shown to have a non-serious illness. NICE NG143 recommendation 1.4.8 explicitly states that a decrease in temperature after antipyretics must not be used to differentiate serious from non-serious illness.1
- Antipyretics and febrile convulsions: a common misconception to address. Many parents give paracetamol to prevent a febrile fit. NICE NG143 recommendation 1.6.1 states that antipyretic agents do not prevent febrile convulsions and should not be used for this purpose.1 This is a common belief that pharmacists are well placed to correct.
- Consider sepsis in any febrile child who is rapidly deteriorating. A child who appears to be worsening quickly, is difficult to rouse, has become mottled, or whose parent reports a dramatic and sudden change from normal behaviour should raise immediate concern for sepsis regardless of which specific features are present.4 Think: could this be sepsis?
- Consider UTI in any child under five with unexplained fever. NICE NG143 explicitly states that UTI should be considered in a baby or child under five with fever and no obvious source. This applies particularly where urinary symptoms, reduced fluid intake, abdominal pain, loin tenderness, or an otherwise unexplained temperature is reported. Refer to GP or NHS 111 for urine testing if UTI is suspected.1, 3
- Learning disability: apply the traffic light framework with care. NICE NG143 advises that a child's learning disability should be taken into account when interpreting the traffic light table. Behavioural cues such as alertness, response to social cues, and level of distress may be harder to assess. Apply a lower threshold for referral.
- Aspirin must not be given to children under 16. Aspirin is contraindicated in children and young people under 16 years because of the risk of Reye's syndrome, a rare but potentially fatal condition affecting the liver and brain.5 Paracetamol or ibuprofen, used according to the licensed product instructions, are the appropriate options. Ibuprofen is not licensed for infants under three months of age or under 5 kg.6
If a parent describes a child who is unresponsive, has a non-blanching rash, or has had a seizure lasting more than five minutes, advise 999 immediately without waiting to gather a full history.
🛑 FEVER: A Counter Assessment Framework
When a parent presents at the counter with a febrile child, this framework helps structure assessment quickly before asking detailed questions.
Look at the child. Pale, mottled, ashen, or blue-tinged? Lips normal? A quiet, disinterested child who is not looking around is telling you something before any questions are asked.
Is the child making eye contact? Responding to their parent? Smiling or interested in their surroundings? Does not wake or will not stay awake is a red feature.
What specifically worries them? Has the child's behaviour changed dramatically? Are they more worried than usual? Parental concern is a valid clinical signal and lowers the threshold for referral (NICE NG143).
Any rash? Press a clear glass against it: if it does not fade, treat as possible meningococcal disease and call 999. Any limb swelling or is the child not using an arm or leg?
Any red feature, amber feature, infant under 3 months with temperature 38°C or above, or significant parental concern? Escalate rather than reassure.
A non-blanching rash in a febrile child should be treated as possible meningococcal disease and requires an immediate 999 response. A non-blanching rash can have other causes, but the emergency action is the same.
The NICE NG143 traffic light system: applying it at the counter
NICE NG143 provides a three-tier traffic light framework for assessing the risk of serious illness in a febrile child.1 Community pharmacists are explicitly included in section 1.3 as practitioners performing remote assessment. This is a pharmacy-focused summary and not an exhaustive reproduction of the NICE traffic light table. Where vital signs such as heart rate, respiratory rate, and oxygen saturation are listed, they apply when reported by a parent, measured by a colleague with equipment, or visible from observation.
- Red features (high risk): any one red feature indicates high risk and requires urgent action. Features include pale, mottled, ashen, or blue skin, lips, or tongue; no response to social cues; appearing ill to a healthcare professional; does not wake or, if roused, does not stay awake; weak, high-pitched, or continuous cry; grunting; respiratory rate more than 60 breaths per minute; moderate or severe chest indrawing; reduced skin turgor; bulging fontanelle; temperature of 38°C or above in an infant under three months; non-blanching rash; neck stiffness; convulsive status epilepticus; focal neurological signs; or focal seizures. Immediately life-threatening features such as shock, an unresponsive child, or suspected meningococcal disease require 999. Other red features require face-to-face paediatric assessment within 2 hours.
- Amber features (intermediate risk): these suggest intermediate risk and include pallor reported by a parent; not responding normally to social cues; wakes only with prolonged stimulation; decreased activity; nasal flaring; tachycardia above the age-appropriate threshold; respiratory rate above age-appropriate amber thresholds; oxygen saturation of 95% or below in air; crackles; capillary refill time of 3 seconds or longer; dry mucous membranes; poor feeding in infants; reduced urine output; rigors; a temperature of 39°C or above in a child aged 3 to 6 months; fever lasting 5 days or more; swelling of a limb or joint; not using an extremity or not weight-bearing. Amber features without red features require face-to-face clinical assessment; urgency depends on clinical judgement and degree of parental concern.
- Fever lasting 5 days or more: Kawasaki disease. Fever lasting 5 days or more is an amber feature and requires same-day clinical assessment. Any child with fever lasting 5 or more days should be assessed by a clinician for Kawasaki disease, a condition causing inflammation of blood vessels that can lead to coronary artery complications if untreated. Additional features may include bilateral red eyes without discharge, cracked lips or strawberry tongue, rash, swelling and redness of the hands and feet, and enlarged neck lymph nodes. These features may not all be present simultaneously. Arrange same-day clinical assessment via GP, NHS 111, or the Emergency Department depending on severity and parental concern.
- Green features (low risk): normal skin colour; responds to social cues; content or smiles; stays awake or wakes quickly; strong normal cry; normal skin and eyes; moist mucous membranes. Children with green features and none of the amber or red features can be managed at home with safety-netting advice. Safety-netting is not optional: NICE NG143 specifies that parents managed at home must be told clearly when to seek further help.
When a child is brought to the pharmacy counter, look at them first. A child who is alert, smiling, making eye contact, and responding to their parent is providing reassuring information before any questions are asked. A pale, quiet child who does not respond to a parent's voice in a busy pharmacy is a clinical concern.
What to do in pharmacy
Advise parents to: offer regular fluids (breast milk or formula for infants; water or diluted juice for older children); dress the child lightly; keep the room at a comfortable temperature; use paracetamol or ibuprofen if the child appears distressed. These medicines should not be used solely to reduce temperature, must not be given at the same time, and should only be alternated if distress persists or returns before the next dose is due. Ibuprofen is not licensed for infants under three months or under 5 kg. Aspirin must not be given to children under 16.
Check the child during the night: parents should not leave a febrile child unmonitored overnight without a safety-net plan. If the child's condition changes significantly, they should seek further advice promptly. Keep the child away from nursery or school while the fever persists.
Tell parents to seek further help or call NHS 111 if: the fever persists beyond five days; the child develops any red or amber feature; the child appears to be deteriorating rather than improving; or the parent becomes more worried despite home care advice.
Key takeaways
- Under three months with any temperature of 38°C or above is high risk regardless of appearance: arrange urgent same-day assessment without delay.
- A non-blanching rash in a febrile child is a medical emergency: call 999 immediately without waiting to gather further history.
- Do not use the response to paracetamol as reassurance: a child with serious bacterial infection may feel better temporarily after an antipyretic dose.
📚 References
- National Institute for Health and Care Excellence. Fever in under 5s: assessment and initial management. NG143. London: NICE; 2019 [updated 2021]. Available from: https://www.nice.org.uk/guidance/ng143
- National Institute for Health and Care Excellence. Fever in children. NICE Clinical Knowledge Summary. London: NICE; 2023. Available from: https://cks.nice.org.uk/topics/fever-in-children/
- National Institute for Health and Care Excellence. Urinary tract infection in children. NICE Clinical Knowledge Summary. London: NICE; 2023. Available from: https://cks.nice.org.uk/topics/urinary-tract-infection-children/
- National Institute for Health and Care Excellence. Sepsis: recognition, diagnosis and early management. NG254. London: NICE; 2025. Available from: https://www.nice.org.uk/guidance/ng254
- NHS. Can I give my child aspirin? London: NHS; 2023. Available from: https://www.nhs.uk/common-health-questions/medicines/can-i-give-my-child-aspirin/
- Joint Formulary Committee. British National Formulary for Children (BNFc). London: BMJ Group and Pharmaceutical Press. Available from: https://bnfc.nice.org.uk