Fever
A fever, or pyrexia, is when the body's temperature rises above normal.
What should my temperature be?
The average normal body temperature taken in the mouth is 37°C (98.6°F), but anywhere between 36.5°C and 37.2°C (97.7°F and 99°F) may be normal. Normal armpit temperatures are 0.2°C to 0.3°C lower than this.
A temperature of 38°C (100.4°F) or above is usually considered to be a significant fever - you should measure it again after two to three hours with a reliable thermometer.
Causes
Fever occurs when certain chemicals are released by the immune system, usually as a result of infection or inflammation. In the past, many infections proved to be fatal. Today there are effective treatments for most infections. However, fever is an important sign that someone is ill and a cause should always be established.
Other causes include any condition where there's inflammation, eg arthritis, trauma and inflammatory bowel disease.
Fevers of unknown origin
Sometimes doctors simply can't establish the cause of a persistent fever. It's then called a pyrexia of unknown origin (PUO ). Special tests may be needed to pinpoint the cause and detect hidden abscesses or unusual infections.
When to contact a doctor
Fever is rarely harmful, but at very high temperatures it can cause problems. For example, some small children with a high fever will have a seizure, known as a febrile convulsion.
A high fever may also be a sign of serious illness. Call your doctor if you're at all worried, especially if:
- you suspect an infection, which might need antibiotic treatment
- it's in a very young child
- the child becomes unusually sleepy or doesn't respond
- the fever is higher than 38.5°C (101.3°F)
- the child won't take fluids
- a child or adult has a stiff neck, an unusual rash or difficulty breathing
Treatment
Not every fever needs medical attention, but if it's a young child, if the temperature continues to rise and if there are other worrying symptoms, contact your doctor.
There are several things you can do to help bring the temperature down and make the person more comfortable:
- Keep the room at a comfortable temperature, and make sure that fresh air is circulating.
- Make sure they drink plenty of water to prevent dehydration.
- Take off excessive layers of clothing. Small babies or children may be left in a thin vest.
- Sponge skin surfaces with cool water.
