Fever

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

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What is a fever?

Your child’s normal body temperature can vary depending on both their age and the time of day. It can range between 36.5 and 38oC. A temperature higher than this is known as a fever.

A temperature of 38oC or more in a baby under 3 months of age, and 38.5oC or more in older infants and children, is considered high.

If you think your child has a fever, measure the temperature with a thermometer. Follow the manufacturer’s directions to get an accurate reading. Plastic tape thermometers on the forehead are not recommended as they are not reliable.

Fever is usually a sign of infection in the body. Infections like colds and flu are very common, especially in pre-school children: Preschool-aged children can have up to 5 to 10 infections a year.

Fever is a natural process

Fever shows us that the body is working to fight infection. Fever is a natural response and in itself is not harmful. So it is not usually necessary to treat a fever.

However, children often feel uncomfortable and unwell when they have a fever. Giving your child pain relief medication such as paracetamol or ibuprofen may help them feel more comfortable. Give your child the dose that is recommended on the packaging for their age and weight. Not all fevers respond to medicines, and this does not mean your child has a serious illness.

Fevers may occasionally bring about febrile convulsions in a few children.  A febrile convulsion is a seizure associated with a high body temperature. While worrying for parents, febrile convulsions usually do not have long term complications. They affect up to 1 in 30 children under the age of 5. This means 29 out of 30 children will never have a febrile convulsion, no matter how high their temperature might go. Pain relief medicines have not been shown to stop or reduce febrile convulsions.

What causes fever?

Fever is most often caused by a virus (such as colds and flu). Viral infections are more common than bacterial infections and do not need antibiotics as these medicines do not cure viruses. Most fevers will pass on their own.

Less often, fevers are caused by a bacterial infection, and these are usually treated with antibiotics.

Rarely, bacteria can cause infection of the urine, lungs (pneumonia), blood and brain (meningitis).

In very young babies it is important to find out the cause of the fever. 

When do you need to see a doctor?

Children should visit their GP first for assessment. Your child’s GP can then identify if further review in a hospital is needed.

Your child needs to see a doctor if they have a fever and:

  • your child is very young (less than 3 months old)
  • your child seems very sick
  • your child has a chronic illness and your doctor has told you to seek help for fever

You also need to see a doctor if your child has:

  • pain – especially headache, tummy or limb pain
  • difficulty swallowing
  • problems with breathing
  • a rash
  • vomiting
  • neck stiffness or light is hurting their eyes
  • bulging of the fontanelle (the soft spot on babies’ heads)
  • drowsiness, sleepiness or irritability
  • had a fever for more than three days
  • travelled overseas recently
  • had contact with someone with a serious infection

Older children (over 3 years) who have a cold, but are not very sick, generally do not need to see a doctor for fever.

Caring for your child at home

  • Dress your child in appropriate clothing so they are comfortable - not shivering or sweating.
  • Give your child plenty of fluid to drink; children with a fever need more fluids than usual.
  • Sponging with water and fanning children with fevers is not recommended.
  • Watch your child for signs that their illness is getting worse.  
  • See a doctor if your child is getting sicker.
  • In general, return to daycare, preschool or school when your child is well. Let your care provider know your child has been sick. If you have seen a doctor, discuss this with them as exclusion periods will vary depending on your child’s illness.

You can call HealthDirect on 1800 022 222 for further health advice.

Some common questions

Can teething cause a fever?

Children who are teething may have a fever up to 380C, but over 380C the fever is more likely due to an infection.

My child has a fever even after pain relief medicine. Should I be worried?

Not if your child is feeling better and other symptoms have improved. Pain relief medicine may not make the fever go away but is used to help your child feel better.

Can I give my child aspirin?

Do not give your child aspirin unless specifically prescribed by a doctor.

Remember

  • Fevers are common in children and mostly caused by viral infections.
  • If your child seems well and is happy, there is no need to treat a fever.
  • Help your child drink plenty of fluids.
  • See a doctor if your baby under 3 months has a temperature of 38oC or more.
  • Watch your child for signs of the illness getting worse.
  • See a doctor if your child seems to be getting sicker.
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The Sydney Children's Hospitals Network
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Hunter New England Kids Health
www.hnekidshealth.nsw.gov.au

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