Fever in children

Also called High temperature in children, Febrile convulsion

A symptom, not an illness. The number matters far less than how the child looks.

What it is

Fever is the body's normal response to infection. In children it is extremely common and almost always caused by a self-limiting viral illness.

The single most useful principle: treat the child, not the thermometer. A child with a temperature of 39.5 who is playing and drinking is far less concerning than a child at 38 who is floppy, mottled and not responding normally.

The NICE traffic light system exists precisely to move parents and clinicians away from the number and towards the appearance.

Febrile convulsions affect around 1 in 20 children between six months and five years. They are frightening to watch and almost always harmless, and they do not mean the child has epilepsy.

Signs you might notice

Green, low risk: normal colour, responds normally, content, strong cry or not crying, normal skin and eyes, moist mouth.

Amber: pallor, not responding normally, reduced activity, poor feeding, dry mouth, reduced wet nappies, a fever for five days or more.

Red, urgent: pale, mottled, ashen or blue; no response to social cues; unrousable; weak, high-pitched or continuous cry; grunting; rapid breathing; reduced skin turgor; a non-blanching rash; a bulging fontanelle; neck stiffness; a fit.

Any fever in a baby under three months is a red flag regardless of how they look.

How it can affect day-to-day life

Parents are frequently told they are over-anxious and equally frequently told they should have come sooner. Neither helps, and the fear of wasting anybody's time is what causes dangerous delay.

The rule worth repeating: if a child gets worse after being seen, go back. Being assessed once does not settle the question forever, because illness evolves.

Paracetamol and ibuprofen are for comfort, not for lowering the number, and they should not be used purely to bring a temperature down or alternated routinely.

Supporting someone well

Look at the child, not the thermometer. Colour, activity, responsiveness, breathing and fluid intake.

Keep fluids going. Small amounts often. Wet nappies are the practical measure in babies.

Do not overwrap or cold-sponge. Neither helps and both can distress.

Use paracetamol or ibuprofen if the child is distressed, not to normalise a number.

Check for a non-blanching rash with a glass, and do not wait for it. See meningitis.

During a febrile convulsion: put the child on their side, time it, do not restrain, do not put anything in the mouth. Call 999 if it lasts more than five minutes or is their first.

Go back if things change. Always.

Where to get help

Call 111 for advice, or 999 for any red feature.

Any fever in a baby under three months needs same-day assessment.

The NICE traffic light table is available free and is worth having on a phone.