Fever

Fever; temperature; degrees; infection; virus; aspirin; paracetamol; Reye's; syndrome; bath; drinks; thermometer; rectal; fit; convulsion; febrile; shiver; sponge; illness; ibuprofen; low;

Contents

• What causes fever?
• When to take a child’s temperature
• How to take a child’s temperature
• When to see a doctor
• Febrile Convulsions
• What to do
• Paracetamol
• Ibuprofen
• References

Fever is when the temperature of the body rises above normal, generally above 38 degrees (38ºC) when the temperature is taken under the arm or in the mouth. Fever usually occurs as a result of an infection.

The normal body temperature varies between about 35.8ºC and 37.4ºC. Different people may have slightly different normal temperatures, and each person’s normal body temperature will vary a little at different times of the day (up to 1ºC). A person's hands and feet can be a lot cooler than 35.8ºC, but the temperature inside their chest, abdomen and head will remain stable.

If a child is very unwell, or has been exposed to very cold conditions, a temperature of 35.5º or lower could mean that there is a serious health problem.

All babies under 12 months old should be seen by a doctor if they have a fever or appear unwell.

What causes fever

• Fever is one of the ways that the body fights an infection.
• In children, most fevers are caused by viral infections. Most of these infections are not serious, even if the temperature is high for a short time (eg. over 40ºC).
• Some fevers are caused by bacterial infections, such as ear infections and tonsillitis, and sometimes children will become well more quickly if they have antibiotics for these infections.
• It is common for young children to have many mild infections which cause fevers – often 5 to 10 viral infections each year.
• Small rises of body temperature can happen in hot weather, or after a hot bath, and after exercise (including when a baby cries vigorously), but these will not cause a rise in temperature to or above 38ºC.

When to take a child's temperature

• It is not necessary to know what a child's temperature is.
• Other signs such as feeling hot when touched, crying, being unusually sleepy, vomiting, pain or refusing to drink can tell you how sick your child is.
• Many parents or carers will take a child’s temperature when the child feels warmer than usual, is irritable and miserable, and looks unwell, to confirm that the child does indeed have a fever.
  

How to take a child's temperature

• One way of knowing whether a child has a fever is to compare how hot child's body feels compared to your own body. You don't need to know just how high the temperature is. It would be best to compare the temperature of a child's chest or tummy with yours, not checking the forehead.
• Under the arms (axillary temperature) – this can be used for all children, and is safer than measuring the child's temperature by putting the thermometer in a young child's mouth. 
  • Place the thermometer high in the armpit and then place the arm down by the child’s side.
  • Read the thermometer after 3 minutes, or follow the instructions that come with an electronic thermometer.
• Mouth (oral temperature) – this can be used for many children over 5 years old, but if the child can't sit still for three minutes, it would still be best to take the temperature under the arm.
  • Place the thermometer as far under the tongue as possible and get the child to keep his mouth closed around the thermometer.
  • Read the thermometer after 3 minutes, or follow the instructions that come with an electronic thermometer.
  • Do not take a child’s temperature this way if the child has recently had a cold drink or warm one.
• Ear (tympanic temperature) – a special ear thermometer can be used. These thermometers are expensive and not as accurate as taking the temperature under the arm or in the mouth.
• Bottom (rectal temperature) – this method can also be used, but is usually not needed.

When to see a doctor

• Children with fevers are usually quieter and less active than usual.
• See your doctor if your child:
  • has a high fever, for example over 40º
  • is becoming more unwell
  • is more difficult to wake up
  • has a rash
  • is vomiting and has diarrhoea more than a couple of times
  • will not drink
  • has cold hands and feet despite have a fever
  • has pale or blotchy skin
  • has pain.
• See your doctor if the fever does not settle when you have given your child paracetamol (or ibuprofen for babies and children over 3 months old).
• All babies under 12 months old with fever should be seen by a doctor.
• See your doctor if you are worried about your child’s health.

Febrile Convulsions

• Some children under the age of 6 years have convulsions (fits) with high fevers.
• This is usually due to the temperature rising quickly, not the actual temperature that is reached.
• These are frightening to watch, but generally do not harm the child.
• It is important to have your child seen by a doctor to find out what has caused the fever.
• See the topic 'Febrile convulsions' for more information.
• Note: paracetamol or ibuprofen do not appear to help prevent febrile convulsions.
  

What to do

A fever by itself can cause a child or older person to feel unwell and tired and to have a headache.

A fever by itself does not cause a health problem (the 'problem' is whatever has caused the fever), but a rapid rise in temperature can trigger a febrile convulsion. Febrile convulsions (fits) caused by a fever rarely cause any ongoing health problems (see Febrile convulsions below).

• The main thing you can do for fever is to help your child feel better by comforting, holding, cuddling and soothing her.
• Cover the child in light clothing.
  • When a child has a fever, the child will often feel that she is cold and she may want to be wrapped up in a blanket.
  • Wrapping a child with a fever in a blanket or thick clothes can push the child's temperature up, as the body cannot lose heat through the skin.
• Extra drinks are needed. Give extra breast feeds, water or diluted fruit juice.
• Paracetamol or ibuprofen can be given - they are usually effective in lowering the temperature for a while (maybe a couple of hours), so that the child feels better, but they do not treat the cause of the fever - and the child's temperature will rise again as they wear off.
• Tepid sponging is not recommended.
  • Tepid sponging (sponging with warm water) does not bring a child's temperature down for long; it will go back up as soon as the sponging is stopped.
  • Sponging does not affect the part of the brain that controls temperature.
  • Using cool water can be uncomfortable for a child, and if the child cries or shivers, the body temperature usually goes up, not down.
  • Never place a sleeping, drowsy, or unconscious child or baby in a bath.
• Also avoid fanning the child.

Paracetamol

Paracetamol is often suggested if the fever is high (over 38.5ºC to 39ºC) - for babies over 1 month old, for children and for adults. This does not deal with the cause of the fever, but can help the child feel better and may bring the temperature down for a while (perhaps a couple of hours). The topic 'Using paracetamol or ibuprofen' has more information about these medicines.

How much Paracetamol to give

• The dose of paracetamol needs to be worked out, using the weight of the child, and the strength of the paracetamol mixture.
• Paracetamol for children comes in several different strengths, for babies, for young children and for older children. Paracetamol is also made and sold by many different companies, so it is very important to check every bottle that you use to make sure that you give the right dose.
• Common strengths include:
  • 100 mg in 1 ml (drops for babies – only very small doses are given)
  • 120 mg in 5 mls (syrup for young children)
  • 240 mg in 5 mls (syrup for children over 4 years old).
• We recommend that you give the dose that is written on the bottle or packaging for a child of your child’s weight.
• If your baby or child is taking some other medicine, check that it does not have paracetamol in it, so that she doesn't get a bigger dose than she should.
• Make sure your child gets plenty to drink while taking paracetamol.

How often can it be given?

• Paracetamol can be given every 4 hours, and no more than 5 times a day.
• If your child seems to need it for more than twenty-four hours, check with your doctor to find out what is wrong.
• Taking even the recommended dose for more than one or two days has (rarely) caused liver damage in some children who were unwell and dehydrated.
• Older children, weighing over 60kg, who are taking tablets, should not have more than eight 500 mg tablets in any 24 hour period.
• There does not seem to be any benefit from using ibuprofen at the same time as you are giving paracetamol.

Ibuprofen

• Ibuprofen is another medicine that can be given for fever in children over 3 months of age. The topic 'Using paracetamol or ibuprofen' has more information about these medicines.
• It does not appear to be better than paracetamol.
• There does not seem to be any benefit from giving it at the same time as paracetamol.
• We recommend that you give the dose that is written on the bottle or packaging for a child of your child's weight.
• Doses can be given 6 to 8 hours apart, with no more than 3 doses in 24 hours.
• Make sure your child gets plenty to drink while taking ibuprofen. Ibuprofen should not be used if a child may be dehydrated (eg. is vomiting or has diarrhoea).
• If your child has asthma ibuprofen might trigger wheezing. It is generally better to use paracetamol.
• Older children weighing over 40kg and taking tablets should not have more than three doses of 400mg in any 24 hour period.

ALERT: Never give aspirin to a child under the age of 16 years. It can cause a rare but very serious illness called Reye's Syndrome.

The topic 'Feeling sick' has suggestions for caring for a sick child.

References

Women's and Children's Hospital (South Australia). ‘Fever in children: guidelines for families’, April 2007

Australian Pharmaceutical Prescriber's Guide (APPG) 'Nurofen for children'.

Bernath VF, Anderson JN, Silagy CA, 'Tepid sponging and paracetamol for reduction of body temperature in febrile children', (a literature review) Medical Journal of Australia, Vol. 176, 4 February 2002.

The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor, or ring the Parent Helpline on 1300 364 100 (local call cost from anywhere in South Australia).

This topic may use 'he' and 'she' in turn - please change to suit your
child's sex.