Fever in children

Published by Bupa's Health Information Team, March 2011.

This factsheet is for people who have a child with a fever, or who would like information about it.

A child's body temperature is usually between 36.5°C and 37.5°C. A fever is a body temperature above this range.

About fever in children

A fever is a high temperature. Fever isn't an illness in itself; it’s usually caused by a virus or bacterial infection. Fever is thought to be part of your body's natural response to an infection.

Fevers are common in young children. They are usually caused by viral infections and clear up without treatment. However, a fever can occasionally be a sign of a more serious illness, such as a severe bacterial infection of the blood (septicaemia), urinary tract infection, pneumonia or meningitis.

Symptoms of fever in children

If your child has a fever, he or she will have a body temperature above 38°C.

As well as having a high temperature, your child may also: 

• feel tired
• look pale
• have a poor appetite
• be irritable
• have a headache or other aches and pains
• feel generally unwell

In some children a sudden increase in body temperature can lead to seizures (also known as fits), which are called febrile convulsions. During a febrile convulsion, part or all of your child's body may shake and twitch and your child’s eyes may roll back in his or her head. Although febrile convulsions can be frightening, they usually last no longer than six minutes. Your child may seem confused immediately after the convulsion, but he or she is likely to make a full recovery.

Fever can occasionally be a sign of a serious infection. Contact your GP immediately or go to hospital if your child:

• is unusually sleepy or difficult to wake up
• has bluish or mottled skin
• has cold hands and feet
• has a weaker than usual, high pitched cry or won’t stop crying
• has difficulty breathing or is breathing very quickly
• has a stiff neck
• is vomiting
• develops a rash that doesn’t disappear when pressed
• has a fit

You should also contact your GP if your child’s fever lasts longer than five days. 

Always seek medical advice if your child develops a fever soon after an operation, or soon after travelling abroad.

Causes of fever in children

Most fevers are caused by common viral infections that go away on their own, such as the common cold. Sometimes a fever can be caused by something more severe, such as an ear, bladder or kidney infection. Rarely, a fever can be a sign of a serious illness such as meningitis or septicaemia.

Occasionally, your child may develop a fever as a symptom of a specific condition rather than as a result of an infection. For example, certain blood disorders and autoimmune disorders may cause a fever. In this case, the fever lasts for longer than one associated with an infection.

Fever can also be a side-effect of some childhood immunisations.

Diagnosis of fever in children

You can take your child’s temperature from his or her mouth or armpit using a digital, glass or ear thermometer. Mercury thermometers are no longer recommended. This is because there is a risk the thermometer could break and release the mercury, which is poisonous, into your child's body.

You may find it easier to take the temperature from the armpit as it may be difficult for your child to keep a thermometer in his or her mouth. However, bear in mind that these measurements are less accurate as the armpit is slightly cooler. To take your child’s temperature this way, place the thermometer under his or her armpit, directly against the skin, and hold his or her arm gently against the chest.

To take your child’s temperature by mouth, place the thermometer under your his or her tongue for two to three minutes.

If your child has a temperature of over 38°C and you’re concerned, contact your GP. He or she will ask about your child's symptoms and can advise whether your child needs to be examined. If so, your GP will take your child’s temperature and measure his or her heart rate and breathing. Your GP may also ask about your child’s medical history. It may help if you keep a record of your child's temperature and other symptoms so that you can give clear information to your GP.

There is likely to be an obvious cause for your child’s fever, so he or she may not need to have further tests. However, if your child’s fever lasts longer than a few days and the cause isn’t clear, your GP may also take a blood sample and/or a urine sample. If your GP is concerned about your child’s symptoms, he or she may be referred to a paediatrician (a doctor who specialises in children’s health) and, very rarely, your GP may ask for emergency medical help.

Treatment of fever in children

Usually your child's fever will be caused by a viral infection and will get better on its own. Monitor your child's fever by regularly checking his or her temperature.

Self-help

Many parents and carers spend a lot of time trying to bring down their child’s fever. However, a fever is part of the body’s natural response to infection and can often be left to run its course provided your child is drinking enough and is otherwise well. If your child is having trouble drinking, trying to reduce his or her temperature may help with this. This is important in preventing your child from becoming dehydrated, which can lead to more serious problems. As a guide, your child's urine should be pale yellow – if it's darker, your child may need to drink more fluids.

Keep your child away from school or nursery while he or she has a fever.

Medicines

You can try paracetamol or ibuprofen to reduce your child’s temperature if he or she is particularly distressed. Don’t give your child these medicines to reduce temperature if he or she is otherwise well, or to prevent a febrile convulsion.

Don’t give your child paracetamol and ibuprofen together. However, if the first medicine you try doesn’t help, you can try the other one later.

You can buy medicines that are suitable for children from a pharmacy without a prescription. Always read the patient information leaflet that comes with your child’s medicine and if you have any questions, ask your pharmacist for advice.

If your child has a bacterial infection, your GP may prescribe him or her a course of antibiotics.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.