What temperature counts as a fever in a child?

A fever in a child is usually defined as a body temperature of 38°C (100.4°F) or higher. Fever is a common response to infection and is most often caused by viral illnesses such as colds or flu.

Is fever dangerous in children?

In most cases, fever itself is not dangerous. It is a normal part of the body's immune response to infection. What matters more is how your child is behaving and whether there are other concerning symptoms.

How can I reduce my child's fever at home?

Make sure your child drinks plenty of fluids, allow them to rest, and keep them comfortably dressed. Paracetamol or ibuprofen can help reduce fever and make your child feel more comfortable if they are distressed.

When should I seek medical advice for a child with fever?

You should seek medical advice if your baby is under three months old with a fever, if your child has difficulty breathing, persistent vomiting, a rash that does not fade when pressed, or if they appear unusually drowsy or difficult to wake.

How long can a fever last in children?

Most viral infections causing fever resolve within three to five days. If your child's fever lasts longer than this or if symptoms worsen, it is advisable to seek medical assessment.

Managing Fever in Children: When to Worry and When to See a Doctor

Dr Shiri Lejay
6 days ago
3 min read

Fever is one of the most common reasons parents worry about their child's health, but in most cases, fever itself is not dangerous. It's actually a sign that your child's immune system is working to fight an infection, usually a virus. Understanding when you can safely manage fever at home and when to seek medical help will give you confidence in caring for your unwell child.

What Is Fever?

Fever is defined as a body temperature of 38°C (100.4°F) or higher. Most childhood fevers are caused by viral infections such as colds, flu, or other common childhood illnesses that will resolve on their own. Young children can have up to 10-12 febrile illnesses per year, particularly during their first few years in nursery or school when they're building their immune systems. While this can feel overwhelming for parents, it's a normal part of childhood development.

The height of the fever doesn't always correspond to how serious the illness is - a high temperature can occur with a mild viral infection, while a serious illness might cause only a moderate fever.

When Fever Requires Urgent Medical Assessment

Babies under 3 months old: Any fever of 38°C or higher in a baby under 3 months requires urgent medical assessment. Young babies can deteriorate quickly, and infections at this age need to be evaluated promptly.

Beyond the first three months, most fevers can be managed at home, but certain warning signs mean your child needs urgent care:

A non-blanching rash (one that doesn't fade when pressed with a glass)
Difficulty breathing or breathing much faster than usual
Unusual drowsiness, difficulty waking, or reduced responsiveness
Persistent vomiting or refusing all fluids
Severe headache or stiff neck
Seizure or fit
Your child seems very unwell or you're seriously concerned
Fever lasting 5 days or more

Managing Fever at Home

For most children over 3 months with fever and no red flag signs, home care is appropriate.

How your child looks and behaves is more important than the exact temperature number. You don't need to wake your child overnight to check their temperature if they're sleeping comfortably. Use a digital thermometer under the arm (axillary) for all ages, or in the ear (tympanic) for children over 6 months.

Key home care measures:

Encourage regular fluids - offer small amounts frequently if they're reluctant to drink
Dress your child in lightweight clothing and keep the room comfortable
Don't bundle them up or use cold baths
Watch for signs of common viral infections: runny nose, cough, mild rash - these are reassuring

Monitor whether your child is drinking, passing urine regularly, can be distracted or comforted, and makes eye contact. A child who can play, even if not as energetically as usual, is generally doing well.

Pain and Fever Relief

The purpose of medication is to make your child more comfortable, not simply to bring the fever down. If your child has a fever but is comfortable, playing, and managing to eat and drink, there's no need to give medication.

Paracetamol: From 3 months of age (2 months only for post-vaccination fever)

Follow age-based dosing on the bottle
Every 4-6 hours as needed, maximum 4 doses in 24 hours

Ibuprofen: From 3 months of age (if over 5kg)

Follow age-based dosing on the bottle
Every 6-8 hours as needed, maximum 3 doses in 24 hours
Give with or after food or milk

If paracetamol alone keeps your child comfortable, stick with that - ibuprofen has a slightly higher side effect profile. However, if your child has a very high fever or is very uncomfortable, you can give both medications at the same time if necessary.

When to Seek Medical Advice

Seek medical advice if:

Fever persists for 5 days or more
Signs of dehydration (reduced wet nappies, dry mouth, no tears when crying)
Your child develops new symptoms or seems to be getting worse
Your instinct tells you something isn't right

Our Private Paediatricians at Central Health London offer same-day appointments for assessment of fevers and infections, providing rapid access to specialist care when you need reassurance or expert evaluation.

Helpful Resources

Apps to help assess your child's symptoms:

NHS Child Health app - advice on managing childhood illnesses
HANDi Paediatrics app - guidance on common childhood illnesses
Lullaby Trust Baby Check app - helps assess how unwell your baby is

This advice is based on NICE clinical guidelines on fever in under 5s.

Trust Your Instincts

You know your child best. If something doesn't feel right, seek medical advice. Healthcare professionals would always rather check a child and provide reassurance than have you worry at home. Early assessment when you're concerned is always appropriate and can provide valuable peace of mind.