Your body’s normal temperature is between 36 and 36.8 degrees Celsius.
A high temperature or fever, for most people, is when your body temperature is 38C or higher. This can be a sign that you are unwell. It usually means you have an infection such as a cold. But it can also be due to more serious infections. So it's important to look at all your symptoms.
Even if you don’t have a high temperature you may still be seriously ill.
Fever in children
In children, any temperature of 38 degrees Celsius or above is considered high. High temperature is common in young children. The temperature usually returns to normal in 3 or 4 days.
Symptoms of a high temperature in children
While high temperatures are usually caused by minor illnesses they can be a sign of serious infections. This is why it is important to check whether your child is alert and responding to you.
Your child can still be sick even without a high temperature. If you are worried that your child may be seriously ill, get medical help immediately even if there is no high temperature.
There is a low risk of serious illness if your child:
- is content and smiling
- stays awake
- is taking drinks
- is responding normally to people
There is a high risk of serious illness if your child:
- cannot be woken up or if woken, does not stay awake
- has a weak or high-pitched continuous cry
- has pale or mottled (blotchy) skin
- keeps vomiting
- is grunting, if they are a baby or breathing very fast
Checking a high temperature
If your child has a high temperature they might:
- feel hotter than usual to touch - on their forehead, back or tummy
- feel sweaty or clammy
- have red cheeks
Treatment for a child with a fever
It's rare for a fever to be a sign of anything serious.
You can usually look after your child or baby at home. The temperature should go down over 3 or 4 days.
Dress your child normally. Children with high temperatures should not be either underdressed or overwrapped. Do not use a cool cloth or sponge to get their temperature down.
Give your child plenty of fluids. Give them food if they want it. Check on your child regularly during the night.
Talk to your pharmacist and use either paracetamol or ibuprofen to reduce your child's temperature and to relieve the pain. You can give your child paracetamol and ibuprofen if they are already on an antibiotic.
Remember, an antibiotic will not reduce a fever or relieve pain.
Start by giving your child either paracetamol or ibuprofen. If the one you started with doesn’t work try giving them the other. You can give both together safely, provided you do not give more than the recommended dose for your child’s weight.
High temperature in adults
Many things can cause a high temperature in adults but it usually means you have an infection such as a cold or flu. However, a high temperature can also be due to other infections so it is important to look at all your symptoms.
A high temperature may be a cause for concern but is rarely a reason to panic. If you feel unwell or if you have a high temperature for more than 3 days, go to your GP.
Talk to your GP
Get an urgent GP appointment if your child:
- is under 3 months old and has a temperature of 38 degrees Celsius or higher, or you think they have a fever
- is 3 to 6 months old and has a temperature of 39 degrees Celsius or higher, or you think they have a fever
- has other signs of illness, such as a rash, as well as a high temperature
- has a high temperature that's lasted for more than 5 days
- doesn't want to eat, or isn't their usual self and you're worried
- has a high temperature that doesn't come down with paracetamol or ibuprofen. The temperature doesn't need to come down to normal. 38 degrees Celsius is fine. Children usually have temperature for at least 3 days with most infections
- is showing signs of dehydration – such as nappies that aren't very wet, sunken eyes, and no tears when they're crying.
When to go to your emergency department
Call 999 or go to your emergency department (ED) if your child:
- has a fever you can't control
- has a stiff neck
- has a rash that doesn't fade when you press a glass against it
- is bothered by light
- has a fit for the first time
- has unusually cold hands and feet
- has pale, blotchy, blue or grey skin
- has a weak, high-pitched cry that's not like their normal cry
- is drowsy and hard to wake
- finds it hard to breathe and sucks their stomach in under their ribs
- has a soft spot on their head that curves outwards (bulging fontanelle)