Fever is not an illness in itself, but is the sign of an illness. Children get fevers for all kinds of reasons. Most fevers, and the illnesses that cause them, last only a few days. But sometimes a fever will last much longer, and might be the sign of an underlying chronic or long-term illness or disease.
A fever is a high temperature. As a general rule, in children, a temperature of over 37.5 °C is a fever.
It can be worrying if your child has a high temperature, but it is very common and often clears up on its own.
A quick and easy way to find out if your child has a fever is to take their temperature using a thermometer. For information on how to do this, visit www.raisingchildren.net.au.
Check your symptoms with healthdirect’s Symptom Checker to get advice on when to seek medical attention.
Most fevers are caused by infections or other illnesses. A fever helps the body to fight infections by stimulating the immune system (the body's natural defence against infection and illness).
By increasing the body's temperature, a fever makes it more difficult for the bacteria and viruses that cause infections to survive.
Your baby's or child's temperature can also be raised during teething (when the teeth start to develop), following vaccinations or if they overheat due to too much bedding or clothing.
If your child seems to be well other than having a high temperature - for example, if they are playing and attentive - it is less likely that they are seriously ill.
You should contact your doctor urgently, or dial triple zero (000) if your child:
- is under three months of age and has a temperature of 38 °C or above
- is between three and six months of age and has a temperature of 39 °C or above
- is over six months and shows other signs of being unwell – for example, they are floppy and drowsy or you are concerned about them.
If your child has a fever, it's important to keep them well hydrated by giving them plenty of cool water to drink. Even if your child isn't thirsty, try to get them to drink little and often to keep their fluid levels up.
Source: NHS Choices, UK (Fever, childhood)
Last reviewed: August 2015