What counts as a high temperature in adults?

A normal body temperature is around 37°C. A temperature of 38°C or above is generally considered a fever. How you feel matters as much as the exact number — a slightly raised temperature with severe symptoms can be more concerning than a higher one when you feel reasonably well.

How do I bring down a fever at home?

Rest, drink plenty of fluids to avoid dehydration, and keep cool but comfortable. Paracetamol or ibuprofen can help you feel better and lower a high temperature. You do not need to force the temperature down if you are otherwise coping.

How long should a fever last?

Fevers from common viral infections in adults usually settle within a few days. A fever lasting more than about 3 days, or one that keeps returning, should be checked by a GP or NHS 111.

When is a fever an emergency?

Seek emergency help for a fever with a stiff neck, a rash that does not fade under pressure, severe headache, confusion, drowsiness or difficulty breathing. These can be signs of a serious infection such as meningitis or sepsis.

High temperature (fever)

Quick answer

What could high temperature (fever) mean?

A high temperature (fever) is usually a sign that your body is fighting an infection, most often a common viral illness. In adults it often settles within a few days with rest and fluids. You should seek advice if a fever is very high, lasts more than a few days, or comes with other warning signs.

What a fever means

A high temperature, or fever, is usually a sign that your body is doing its job — raising its temperature to help fight off an infection. In adults, most fevers are caused by common viral illnesses such as colds and flu, and settle by themselves within a few days. A normal temperature is around 37°C; 38°C or above is generally considered a fever.

Common causes

Viral infections — colds and flu are by far the most common.
Other infections — such as a chest, urine, ear or throat infection.
After vaccination — a mild, short-lived temperature can be normal.

How unwell you feel overall is just as important as the exact number on the thermometer.

Looking after yourself

Most fevers in adults can be managed at home. Rest, drink plenty of fluids to stay hydrated, and keep cool and comfortable. Paracetamol or ibuprofen can help you feel better and reduce a high temperature, though you do not need to force it down if you are coping. Avoid wrapping up too warmly.

When to get help

Contact a GP or NHS 111 if a fever lasts more than three days, keeps returning, or you feel very unwell — and sooner if you have a weakened immune system or a long-term condition. Treat as an emergency any fever with a stiff neck, a rash that does not fade when pressed, a severe headache, confusion, drowsiness or difficulty breathing, as these can signal a serious infection.

Common questions

What counts as a high temperature in adults?: A normal body temperature is around 37°C. A temperature of 38°C or above is generally considered a fever. How you feel matters as much as the exact number — a slightly raised temperature with severe symptoms can be more concerning than a higher one when you feel reasonably well.
How do I bring down a fever at home?: Rest, drink plenty of fluids to avoid dehydration, and keep cool but comfortable. Paracetamol or ibuprofen can help you feel better and lower a high temperature. You do not need to force the temperature down if you are otherwise coping.
How long should a fever last?: Fevers from common viral infections in adults usually settle within a few days. A fever lasting more than about 3 days, or one that keeps returning, should be checked by a GP or NHS 111.
When is a fever an emergency?: Seek emergency help for a fever with a stiff neck, a rash that does not fade under pressure, severe headache, confusion, drowsiness or difficulty breathing. These can be signs of a serious infection such as meningitis or sepsis.

Sources

NHS — Fever in adults