What temperature counts as a fever in a child?

A temperature of 38°C or higher is generally considered a fever in a child. Under 3 months, any fever of 38°C or above needs prompt medical assessment because infections can progress quickly in young babies.

Should I wake my child to give fever medicine?

If your child is sleeping comfortably, you do not need to wake them. Treat fever when they are awake and uncomfortable — the goal is to reduce distress, not to reach a specific temperature number.

Can I alternate paracetamol and ibuprofen?

Some parents alternate if one alone is not enough, but this is not always necessary and dosing errors can occur. Follow the instructions on the packet, or ask a pharmacist or GP for advice on your child's age and weight.

When should I not give ibuprofen?

Avoid ibuprofen if your child is dehydrated, has chickenpox (unless a doctor advises), has asthma triggered by ibuprofen, or is under 3 months. Paracetamol is usually suitable from 2 months (check product label).

Does a high fever cause brain damage?

Fevers caused by common infections do not cause brain damage. Very high fevers above 40°C are uncomfortable but rarely harmful in otherwise healthy children. Febrile seizures can occur but are usually brief and not dangerous long-term.

Fever in children: When to See a GP

Quick answer

What could fever in children mean?

A fever in children is a temperature of 38°C or higher. It is common and usually shows the body is fighting an infection. Most fevers settle within a few days with fluids and paracetamol or ibuprofen. Seek urgent help for a non-blanching rash, difficulty breathing, or any fever in a baby under 3 months.

Fever is common in children

A fever — a body temperature of 38°C or higher — is one of the most common reasons parents seek medical advice. It is usually a sign that your child’s immune system is fighting an infection, most often a virus. Fever itself is generally not harmful, even when the number on the thermometer looks high.

How your child seems — alert vs floppy, drinking vs dehydrated — matters more than the exact temperature.

Checking your child’s temperature

Use a digital thermometer:

For babies under 4 weeks, an armpit (axillary) temperature is recommended.
For children over 4 weeks, ear or armpit thermometers are suitable — follow the manufacturer’s instructions.

Forehead strips are less accurate. A fever is 38°C or above.

What usually causes fever in children

Viral infections — colds, flu, COVID-19, chickenpox, hand foot and mouth, and many others
Ear infections — common after a cold
Tonsillitis — sore throat with fever
Urinary tract infections — especially in girls; may have no obvious symptoms except fever in young children

Most viral fevers settle within three to five days.

Treating fever at home

Fever medicine reduces discomfort — it does not cure the infection:

Paracetamol can usually be given from 2 months of age, but check the product label as some products are for 3 months and over.
Ibuprofen can usually be given from 3 months if your child is well hydrated, but not for chickenpox unless a doctor advises it.

Follow the age and weight dosing on the packet. Do not exceed the maximum daily dose.

You can also help your child feel more comfortable in other ways:

offer plenty of fluids, little and often
dress them in light clothing and avoid heavy blankets
keep the room comfortably cool
let them rest as much as they need

Sponging with cool water is not recommended — it can cause shivering and raise temperature further.

When fever needs urgent attention

Call 999 if your child:

has difficulty breathing
has a rash that does not fade when pressed with a glass
has a fit (febrile seizure) lasting more than 5 minutes, or their first ever seizure
has blue lips or looks grey
is difficult to wake or unusually floppy

See a GP urgently if:

your baby is under 3 months old with any fever of 38°C or higher
your baby is under 6 months old with a temperature of 39°C or higher
the fever has lasted more than 5 days
your child is not drinking, or is having fewer wet nappies than usual
your child is crying constantly and cannot be soothed

Febrile seizures

Some children (about 1 in 20) have a brief seizure when their temperature rises quickly. This looks frightening but is usually harmless. If a seizure lasts more than 5 minutes, call 999. After a first seizure, see a GP for assessment.

Trust your instincts

Guidelines cannot cover every situation. If you feel something is wrong — even with a normal temperature — contact NHS 111 or your GP. Parents know their children best.

After the fever settles

It is normal for children to be tired and off their food for a few days after a fever. Gradually return to normal activities. See a GP if they are not improving or develop new symptoms.

Common questions about fever in children

What temperature counts as a fever in a child?: A temperature of 38°C or higher is generally considered a fever in a child. Under 3 months, any fever of 38°C or above needs prompt medical assessment because infections can progress quickly in young babies.
Should I wake my child to give fever medicine?: If your child is sleeping comfortably, you do not need to wake them. Treat fever when they are awake and uncomfortable — the goal is to reduce distress, not to reach a specific temperature number.
Can I alternate paracetamol and ibuprofen?: Some parents alternate if one alone is not enough, but this is not always necessary and dosing errors can occur. Follow the instructions on the packet, or ask a pharmacist or GP for advice on your child's age and weight.
When should I not give ibuprofen?: Avoid ibuprofen if your child is dehydrated, has chickenpox (unless a doctor advises), has asthma triggered by ibuprofen, or is under 3 months. Paracetamol is usually suitable from 2 months (check product label).
Does a high fever cause brain damage?: Fevers caused by common infections do not cause brain damage. Very high fevers above 40°C are uncomfortable but rarely harmful in otherwise healthy children. Febrile seizures can occur but are usually brief and not dangerous long-term.

Sources

NHS — High temperature (fever) in children