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.

What is a fever?

Your child’s body temperature ranges between 36.5 and 37.5 oC. A fever is when the body’s temperature is significantly higher than normal when the child’s temperature is taken by a thermometer under the arm. A temperature of 38 oC or more in a baby under three months of age and 38.5 oC or more in older infants and children is considered significantly high.

Fever is usually a sign of infection in the body. Infections such as colds and flu are very common, especially in pre-school children. Young preschool children can have up to five to ten infections each year.

Fever is most often caused by a virus and sometimes by bacteria.  Viral infections are more common and do not need antibiotics as antibiotics do not cure viruses.  Bacterial infections are usually treated with antibiotics.

Is fever good or bad?

Fever is the body's natural response to help fight infection. Fever itself is not harmful, so it is usually not necessary to treat the fever.

However, children with fever often feel uncomfortable and unwell.  Giving pain relief medication such as paracetamol or ibuprofen may be helpful for this discomfort.

Fevers may occasionally bring about febrile convulsions (fits), in up to 1 in 30 children under five years of age. This means 29 out of 30 children will never have a febrile convulsion no matter what their temperature is. Febrile convulsions are not dangerous, but they can be very frightening for parents.  Medicines such as paracetamol or ibuprofen, even when used regularly with fever, have not been shown to stop or reduce the amount of febrile convulsions children have.

Fever itself is not harmful; a fever that does not respond to paracetamol or ibuprofen is no worse than a fever that does. A high fever does not always mean your child has a serious illness.

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

What causes fever?

The most common cause of a fever is a viral infection, for example colds and flu. Other common infections, like ear infections and throat infections, may be caused by a virus or bacteria and the decision to treat the infection with antibiotics will vary.

More serious but less common causes of fever include bacterial infection of the urine, lungs (pneumonia), blood and brain (meningitis).

When do you need to see a doctor?

You need to see a doctor if your child has a fever and:

  • Your child is very young (less than three months old).
  • Your child seems very sick.
  • Your child has a chronic illness & your doctor has told you to seek review promptly if they develop a 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 the light is hurting their eyes.
  • Bulging of the fontanelle (the soft spot on the head in babies).
  • Become drowsy, very sleepy or irritable.

Other special circumstances: if your child has a fever for more than three days; your child has travelled overseas recently; or your child has had contact with someone with a serious infection.

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

At Home Care

  • Dress your child in enough clothing so that they are comfortable and are not shivering or sweating.
  • Give your child plenty to drink; children with a fever need more fluids.
  • Sponging with water and fanning children with fevers is not recommended.
  • Watch your child for signs that their illness is getting worse.  
  • Consult a doctor if the fever does not settle or your child is getting sicker.


  • Fevers are common in children and most are caused by viral infections.
  • If your child seems well and is happy there is no need to treat a fever.
  • Make sure your child drinks plenty of fluids.
  • Babies under 3 months with a high temperature must be seen by a doctor.
  • Watch your child for signs of the illness getting worse.
  • Consult a doctor if the fever does not settle and your child seems to be getting sicker.
The Children's Hospital at Westmead
Tel: (02) 9845 0000
Fax: (02) 9845 3562
Sydney Children's Hospital, Randwick
Tel: (02) 9382 1688
Fax: (02) 9382 1451
Kaleidoscope Children, Young People and Families
Tel: (02) 4921 3670
Fax: (02) 4921 3599

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