Fever in children

Key points about fever in children

  • Fevers, also known as a high temperature, are common in children.
  • An ordinary cold can cause a high fever so a fever by itself does not tell you whether your child is seriously unwell.
  • A fever (temperature higher than 38ºC) is usually caused by an infection such as a cold. It should return to normal (around 37ºC) within a few days.
  • You can take their temperature with a thermometer, read more about thermometers and how to use them. In most cases your tamariki with a fever can be cared for at home.
  • A fever, with or without respiratory symptoms such as a cough or runny nose, could also be a COVID infection. Test for COVID-19 and stay home until well or you're sure they don't have COVID.
Mother on couch cradles son with high temperature
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Fluids: Give your child plenty of fluids to avoid dehydration. Encourage them to eat small, healthy meals or snacks.
Rest: Give them extra rest.
Clothing: Undress your child so they are just wearing a single layer (maybe a singlet and pants). Make sure the room is not too hot or too cold. 
Check them regularly: You may need to give them extra cuddles and let them be closer to you.
Medicine: Give medication if needed and always follow the label to make sure it’s the right dose for your child’s age, weight and illness. See below for information on medication.

Important: babies under 3 months old should be seen by a doctor
  • If your baby is less than 3 months old and has a fever, make sure you consult a healthcare professional.
  • If you are worried about them, take them to your doctor even if they do not have a fever.
  • Some babies may have an unstable temperature with an infection – they may be colder than normal – in a sick baby this is a worrying sign and is a reason to see a doctor urgently.
  • Babies get fevers for the same reasons as older children, but they are not as good at fighting off infections.

It's OK to look after your child, or baby over 3 months old, at home as long as they are drinking and eating well and interacting with you.  

Contact a healthcare provider or call Healthline 0800 611 116 for advice if your child with a fever:
  • has a sore throat or joint pains
  • is drinking less than half of their normal amount of breastmilk or other fluid
  • is having fewer than 4 wet nappies in 24 hours
  • vomited at least half of their feed for the last 3 feeds
  • has frequent and watery poo (diarrhoea)
  • complains or cries when having a wee (mimi)
  • is in pain
  • isn't improving or is getting sicker after 2 days
  • has had a fever for more than 5 days.

Contact a doctor urgently if your child with a fever:

  • is under 3 months old – young babies need a different and more cautious approach
  • looks unwell and you are concerned
  • is very pale or feels cold to touch
  • is floppy, sleepy or drowsy 
  • is becoming less responsive 
  • has an unusual high-pitched cry 
  • has trouble breathing, has noisy breathing or is breathing fast 
  • complains of a stiff neck or light hurting their eyes 
  • has a severe headache 
  • refuses to drink – even small sips 
  • is not doing wee 
  • vomits a lot – and cannot keep sips of replacement drinks down 
  • vomits green fluid (bile) 
  • vomits blood – this may be red or brown or look like coffee grounds if it is not fresh 
  • is in severe pain 
  • is not interested in their surroundings (lethargic). 

Call 111 and ask for an ambulance or go to the nearest hospital if your child with a fever:

  • has blue lips and tongue 
  • has severe difficulty breathing 
  • has any episodes of irregular or stopping breathing 
  • has a worrying rash especially one that does not go away when you press on it  
  • is unconscious or you can't wake them up properly. 

The most common cause of a fever in a child is an infection. The body's natural reaction to infection is to raise the temperature inside the body. This helps to kill the infection. Other causes of high body temperature include:

  • immunisation – this usually causes only mild fever
  • wrapping a baby in too many warm layers of clothing or bedding.

Fever is a normal way for a child to fight an infection. Being hot may make your child feel unhappy or uncomfortable, but the high temperature is very unlikely to cause any long-term problems. Some children have seizures when they have fevers. These look very worrying, but even these febrile seizures are very unlikely to cause long-term problems. Read more about febrile seizures.

If your child is happy, and they are not unwell, you do not need to do anything more. You do not need to treat the fever with a medicine.

Paracetamol

If your child is miserable because of the fever, you can give paracetamol to make them more comfortable. You must follow the dosage instructions on the bottle. It is dangerous to give more than the recommended dose. Read more about paracetamol in children and use our paracetamol dose calculator if you're not sure how much to give them.

You don't need to give babies and children paracetamol before or after immunisation. There is some evidence that paracetamol may reduce the effectiveness of childhood immunisations.

Other medicine

  • If your doctor gives your child ibuprofen, use it only if your child with a fever is miserable.
  • Don't give your child cold and flu medicines.
  • Never give your child aspirin as this may increase the risk of Reye syndrome, which is a rare and serious illness.

Do not routinely prescribe oral antibiotics to children with fever without an identified bacterial infection. The vast majority of children presenting with fever do not have a bacterial infection and therefore will not benefit from being prescribed oral antibiotics. For instance, one study of febrile infants found overall bacteraemia frequency of well below one per cent. Sometimes, in exception to this, oral antibiotics are prescribed to treat an unapparent bacterial infection or prevent development of severe bacterial infection and appear to have beneficial effects, though even the significance of these effects is disputed. Given that inappropriate prescribing of antibiotics is a major cause of antibiotic resistance and antibiotics have adverse effects, it is not considered good clinical practice to prescribe antibiotics in children without a specific bacterial infection. Paediatrics and child health(external link) Choosing Wisely, NZ, 2016

Identifying the risk of serious illness in children with fever(external link) BPAC, NZ, 2010
Fever - neutropenic Starship, NZ, 2014

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Credits: Content shared between HealthInfo Canterbury, KidsHealth and Health Navigator NZ as part of a National Health Content Hub Collaborative.

Reviewed by: Content shared between HealthInfo Canterbury, KidsHealth and Health Navigator NZ as part of a National Health Content Hub Collaborative.

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