What is a fever?

A fever is when your body temperature is higher than normal. Having a fever can also be called ‘having a temperature’.

A normal temperature is around 36℃ to 37℃, although it depends on:

• your age
• what you’ve been doing
• the time of day
• how you take the measurement

You probably have a fever if your temperature is 38℃ or higher.

Fever is diagnosed by taking a person’s temperature. You can take your own temperature, or the temperature of someone you’re caring for, using a thermometer.

You can buy a thermometer from a chemist or supermarket. Different types of thermometers measure temperature through different parts of your body, such as:

• touchless forehead thermometers
• in the ear
• under the armpit
• under the tongue
• in the rectum

Make sure the thermometer is clean.

Check the manufacturer's instructions to find out how to use your thermometer.

If you are caring for a child with a fever, see Fever in children for more information.

What symptoms are related to a fever?

If you have a fever, you will have a high temperature. A high temperature is usually considered to be above 38℃. You may also have other symptoms, such as:

• sweating
• chills
• shivering
• aching muscles and joints

What causes a fever?

Fever is a part of your immune system response. If you have a fever, it is a sign that your body is working hard to get well.

A fever is usually caused by a viral infection such as:

• colds and flu
• COVID-19
• gastroenteritis

However, fever can also be caused by bacterial infections, such as:

• ear infections
• throat infections
• pneumonia
• urinary tract infections
• meningitis

How is the cause of a fever diagnosed?

A doctor can usually find the cause of your fever by asking questions about your symptoms and examining you.

Sometimes, your doctor may need to run some tests find the cause. The type of tests will depend on any other symptoms you have. For example, if you have a runny nose or sore throat, they may take a swab of your nose or throat. If you have symptoms of a UTI – such as burning when you urinate, or needing to urinate often – they may ask for a urine sample.

Make sure you tell your doctor if you have recently returned from an overseas trip.

When should I see my doctor?

If you have a baby under 3 months old with a fever above 38℃, take them to the nearest hospital emergency department immediately.

If you or your child has had a fever for more than three days that isn’t getting better despite self-care, you should see a doctor.

You should also see a doctor as soon as possible if you have a fever and:

• just got out of hospital or had surgery or a medical procedure
• have just returned from an overseas trip
• are receiving treatment for cancer or are taking medicines that supress your immune system
• any other symptoms that you are concerned about

When to seek urgent care

Adults should go immediately to their nearest emergency department if they have a fever and other symptoms such as:

• a severe headache
• sensitivity to bright light
• an unusual skin rash
• a stiff neck
• vomiting
• confusion
• drowsiness
• difficulty breathing
• abdominal (tummy) pain
• hallucinations
• seizures or muscle spasms

If your child has a fever, take them to the emergency department right away if they:

• are under 3 months
• seem dehydrated or won’t drink
• are vomiting
• are drowsy or unresponsive
• have difficulty breathing
• seem very distressed

How is fever treated?

Self-care at home

If you have a high temperature there are several things you can do to help manage your condition. If your fever doesn’t go away, or you are concerned, see your doctor.

Keep hydrated

It’s important to stay well hydrated. Try to drink plenty of clear, non-alcoholic fluids, such as:

• water
• juice
• cordial

Keep cool

Wear lightweight clothing, and avoid using bedding such as blankets, doonas and quilts. These can make you too hot and increase your temperature. Keep the room at a comfortable temperature.

Avoid taking cold baths or sponging. This can actually make you feel more uncomfortable.

Rest

If you have a fever, you should rest and avoid heavy activity until your symptoms go away.

Medicines for fever

Don’t take medicines for fever unless you are experiencing discomfort.

If you’re experiencing discomfort, you can consider pain relief medicines such as:

• paracetamol
• ibuprofen

Before taking any medicine, you should check that it's safe to take them:

• with any medical conditions that you may have
• with any other medicines that you are taking
• if you are pregnant or breastfeeding

Can fevers be prevented?

While they can cause discomfort, fevers are part of your body’s normal immune response. This means that they cannot be prevented if you’re sick, as they occur when your body is working hard to get well.

If your fever doesn’t go away, or you experience other symptoms mentioned above, you can prevent further complications by seeking medical attention.

Complications of fever

Febrile convulsions are seizures (fits) that happen in children because of a fever. They usually happen when your child’s temperature rises quickly.

Febrile convulsions occur in about 1 in every 30 children between the ages of 6 months and 6 years. Most children who have a febrile convulsion won’t ever have another one.

Febrile convulsions have no long-term consequences, but you should talk to your doctor about them if you’re worried.

Resources and support

If you’re worried about your symptoms, you can call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.