Fever in children — when to worry, and what actually helps

About this guide

Fever is the commonest reason parents bring a child to see us, and the commonest reason for a worried message at 2am. Most fevers in children are caused by viral infections that settle in a few days on their own. A small number are the first sign of something that needs treatment quickly. The job for parents, and for us, is to tell the two apart, and that depends far more on how your child looks and behaves than on the number on the thermometer.

This guide covers what a fever is, what helps at home, what does not, febrile seizures, the infections we think about in Singapore, and the warning signs that mean your child should be seen the same day.

What counts as a fever

A fever is a body temperature of 38.0°C or higher. Normal temperature varies through the day and is slightly higher in the evening, so 37.5°C is not a fever.

How you measure matters:

• Under 4 weeks: an electronic thermometer in the armpit.
• From 4 weeks to 5 years: an electronic thermometer in the armpit, or an infrared ear (tympanic) thermometer.
• Older children: ear, armpit or oral electronic thermometers are all fine.
• Forehead strips and forehead “gun” thermometers are convenient for screening but less reliable. If the reading matters, confirm it with an ear or armpit reading.

Trust your own sense of your child as well. Parents are usually right when they say “she feels hot”.

Fever is a response, not the illness

Fever is the body’s normal response to infection. Raising the body temperature helps the immune system work and slows many viruses and bacteria. It is uncomfortable, but a fever from an ordinary infection does not damage the brain, and a child’s temperature does not climb without limit.

Two things follow from this:

• The height of the fever is a poor guide to how serious the illness is. A child with 40°C from a viral infection who is drinking and playing between doses of paracetamol is usually less worrying than a child with 38.5°C who is limp and unusually quiet.
• The aim of treatment is comfort, not a normal thermometer reading. You do not need to bring the temperature down to 37°C, and you do not need to wake a sleeping child to give medicine.

The age rule that matters most

Age changes the advice more than anything else.

Fever in the first three months of life is never something to watch at home overnight.

What helps at home

• Fluids, small and often. Water, milk, diluted juice, ice lollies, soup. Breastfed babies should feed on demand. A feverish child loses more fluid than usual and often does not feel like drinking.
• Light clothing and a comfortable room. Do not bundle a feverish child in blankets, and do not strip them to shivering either.
• Paracetamol or ibuprofen for discomfort. Give them because your child is miserable, achy or not drinking, not because the thermometer says so. Details below.
• Rest, but no need for bed. Let your child do what they feel like doing.
• Keep an eye on them. Check during the night. Watch how much they drink and how many wet nappies or toilet trips there are.

Paracetamol and ibuprofen: doses by weight, not age

Children’s medicines are dosed by weight. The dose on the box is a rough guide by age; if your child is small or large for their age, it will be wrong. We give you the exact number of millilitres for your child’s weight and the strength of the syrup you have at home, and we suggest you write it on the bottle.

• Paracetamol: usually 10–15 mg per kilogram per dose, every 4 to 6 hours as needed, no more than four doses in 24 hours. It can be used from birth (in young babies, only on medical advice).
• Ibuprofen: usually 5–10 mg per kilogram per dose, every 6 to 8 hours as needed, from 6 months of age, and only if the child is drinking reasonably well. Give it with milk or food. Do not use it in a child who is dehydrated, has kidney problems, or if dengue is a possibility (see below).
• Do not give both at the same time. If one is not making your child more comfortable, you can consider the other, but routinely alternating the two invites dosing mistakes.
• Never give aspirin to a child for a fever. It is linked to Reye’s syndrome, a rare but serious illness.
• Check every syrup for its strength. Paracetamol syrup in Singapore comes in different concentrations (commonly 120 mg in 5 mL and 250 mg in 5 mL). The same number of millilitres of the two is not the same dose.
• Suppositories are useful for a child who is vomiting. The dose is still by weight.

What does not help

• Tepid sponging, cold baths and fans are no longer recommended. They make children shiver and cry, and they do not shorten the illness.
• Antibiotics do nothing for viral fevers, which are the majority. We prescribe them when there is a bacterial cause that benefits from treatment, such as a urine infection, strep throat or some ear infections.
• “Fever plasters” on the forehead cool the skin under the patch and nothing else.
• Stopping vaccinations because of a fever. A mild illness is not a reason to delay vaccines; ask us.

Febrile seizures

About 2 to 5 in every 100 children have a febrile seizure: a fit triggered by a fever, usually between 6 months and 5 years of age, and most often on the first day of an illness. They are frightening to watch and are almost always harmless. Most last under five minutes, the child is drowsy afterwards, and there is no lasting damage. Roughly one child in three has another one with a later fever.

If your child has a seizure:

1. Lie them on their side on a safe surface, away from anything hard.
2. Do not put anything in their mouth and do not try to hold them still.
3. Note the time. Most stop within a few minutes.
4. Call 995 if the seizure lasts more than 5 minutes, if breathing looks abnormal, or if your child does not start to recover afterwards.
5. Every first febrile seizure should be assessed by a doctor the same day, to make sure the fever has a simple cause.

Paracetamol and ibuprofen make a child more comfortable, but they do not prevent febrile seizures, so there is no need to medicate a child around the clock for that reason.

Causes we think about

Most fevers in children come from viral infections: colds, flu, RSV, roseola (high fever for three days, then a rash as the fever settles), hand, foot and mouth disease, viral tonsillitis and viral gastroenteritis. Our guide to colds, coughs and fevers in children covers the respiratory ones in detail.

Fevers that need specific treatment include:

• Ear infections in the toddler age group (see our ear infection guide)
• Strep throat in school-age children
• Urinary tract infection, which in babies and toddlers may cause fever with no other clue. This is why we often ask for a urine sample from a young child with a fever and no obvious source.
• Pneumonia: fast breathing, chest indrawing, persistent fever
• Dengue: see the next section
• Kawasaki disease: a rare condition in young children with fever lasting five days or more plus red eyes, red cracked lips, a rash, swollen hands and feet or a swollen neck gland. It needs hospital treatment, which is one reason a fever of five days should always be reviewed.
• Meningitis and sepsis: rare, and the reason the warning signs below exist.

Fever after vaccination is common and expected: usually within 48 hours of most vaccines, and 5 to 12 days after the MMR vaccine. It settles with the usual comfort measures. A fever more than 48 hours after a vaccine is usually something else.

Teething can make a baby grizzly and dribbly, with a slightly raised temperature. It does not cause a true fever of 38°C or more; look for another cause.

Dengue: a Singapore-specific point

Dengue circulates in Singapore all year, with a higher risk in some estates and seasons. In a child, dengue typically causes a high fever with headache, pain behind the eyes, muscle and joint aches, poor appetite, nausea and sometimes a rash, and it is often mistaken for a viral illness in the first days.

Two practical points:

• If dengue is possible, use paracetamol only. Ibuprofen and other anti-inflammatory medicines increase the risk of bleeding in dengue.
• The risky period is often when the fever settles, around days 3 to 7. Warning signs that need urgent assessment: severe abdominal pain, persistent vomiting, bleeding from the gums or nose, blood in vomit or stool, unusual drowsiness or restlessness, cold clammy skin, or passing very little urine.

A simple blood test can diagnose dengue from the first days of fever. If your child has a fever with no obvious cause, especially if there are dengue cases nearby, tell us.

When to see a doctor

Bring your child in, the same day where possible, if:

• Your baby is under 3 months and has a temperature of 38°C or more (go straight to a children’s emergency department if we are closed)
• Your baby is 3 to 6 months and has a temperature of 39°C or more
• The fever has lasted 5 days or more, or it settled and has come back
• Your child is drinking much less than usual, or has had fewer than half the usual number of wet nappies
• There is pain somewhere specific: an ear, the throat, the tummy, passing urine, a limb your child will not use
• A rash has appeared with the fever
• Your child has had a febrile seizure for the first time
• Your child has a long-term condition (heart, lung, kidney, immune problems, or is on medicines that suppress immunity)
• You are worried. That is a good enough reason.

Go to a children’s emergency department or call 995

• A rash that does not fade when you press a glass against it
• Difficulty breathing: fast breathing, grunting, the skin pulling in between the ribs or at the neck, blue lips
• Unusually drowsy, floppy, hard to wake, or a high-pitched or weak cry that is not like your child
• A seizure lasting more than 5 minutes, or a child who does not recover afterwards
• A stiff neck, a bulging soft spot on a baby’s head, or a severe headache with vomiting
• Signs of dehydration: no wet nappies for 8 hours, a dry mouth, sunken eyes, no tears
• A child who cannot be comforted at all, or who is in severe pain
• Any of the dengue warning signs above
• Your instinct says something is seriously wrong

In Singapore, children’s emergency departments are at KK Women’s and Children’s Hospital (KKH) and the National University Hospital (NUH). Call 995 for an ambulance if your child is very unwell.

How we manage fever at our Punggol clinic

Children with fever are seen as walk-ins, Monday to Saturday, and can be booked online. At the visit:

• We assess the child, not the thermometer. How they look, breathe, drink and interact tells us most of what we need to know. We examine the ears, throat, chest, tummy and skin, and check the urine in young children with no obvious source.
• Rapid tests where they change management: a combined respiratory antigen test (COVID-19, influenza A and B, RSV, adenovirus), a rapid strep test for school-age children with a sore throat, urine testing, and blood tests for dengue where indicated.
• A written dose for your child’s weight for paracetamol and ibuprofen, with the strength of the syrup you have at home.
• Clear safety-net advice: what to expect over the next days, what to watch for, and when to come back or go to hospital.
• A medical certificate for school or childcare where needed.
• Prompt referral to KKH or another children’s service when a child needs hospital care, with a letter so that nothing is repeated unnecessarily.

Cross-links

• Colds, coughs and fevers in children: the respiratory causes, what not to give young children, and rapid testing
• Hand, foot and mouth disease: fever with mouth ulcers and a rash
• Ear infections in children
• Common childhood rashes: including the rashes that come with fever
• Childhood vaccinations (NCIS)

Get in touch

Punggol: 658 Punggol East, #01-04, Singapore 820658 · Tel 6312 4589 · Walk-ins welcome Mon–Sat

Joo Chiat: 172 Joo Chiat Road, #01-01, Singapore 427443 · Tel 6920 1952 · By appointment

Email: admin@ktmc.sg

References

• National Institute for Health and Care Excellence (NICE). Fever in under 5s: assessment and initial management. NICE guideline NG143. November 2019, updated 2021. nice.org.uk
• HealthHub, Ministry of Health Singapore. Fever in children. healthhub.sg
• KK Women’s and Children’s Hospital (KKH). Fever in children and Febrile seizures, patient information. kkh.com.sg
• Ministry of Health Singapore and National Environment Agency. Dengue: symptoms and warning signs. nea.gov.sg
• Health Sciences Authority Singapore (HSA). Paracetamol and ibuprofen for children: safe use. hsa.gov.sg
• American Academy of Pediatrics. Clinical report: Fever and antipyretic use in children. Pediatrics. 2011 (reaffirmed 2022).
• McCrindle BW, et al. Diagnosis, treatment and long-term management of Kawasaki disease: a scientific statement from the American Heart Association. Circulation. 2017;135:e927–e999.

This information is for general education only and is not a substitute for medical advice. Doses for children depend on weight, age and the medicine you have at home; please check with our team. v1.0 · September 2026 · Review due September 2028.