When your baby or child has a fever, it's natural to feel worried, especially if they're very young. A high temperature is common in babies and children and is usually a sign that their body is fighting an infection.
Most childhood fevers improve within a few days and can be managed at home. However, it's important to know what temperature counts as a fever, how to keep your little one comfortable and when to seek medical advice.
What temperature is a fever in babies and children?
A temperature of 38°C or above is considered a fever in babies and children.
A child's normal body temperature can vary slightly, but a high temperature is often one of the first signs that they're feeling unwell.
Signs your baby or child may have a fever include:
-
Feeling hotter than usual on their chest or back
-
Sweating or having clammy skin
-
Flushed cheeks
-
Shivering or feeling cold
-
Being unusually tired, irritable or unsettled
-
Feeding less or showing less interest in food
Important: If your baby is under 3 months old and has a temperature of 38°C or above, seek urgent medical advice. For babies aged 3–6 months, a temperature of 39°C or above also requires urgent medical advice.
What causes fever in babies and young children?
Fever is usually the body's natural response to an infection. When your child becomes unwell, their immune system raises their body temperature to help fight the infection.
Common causes of fever in babies and children include:
-
Colds and flu: Viral infections are among the most common causes of fever in children.
-
Ear infections: These may cause a high temperature, earache and irritability.
-
Tonsillitis: A sore throat, difficulty swallowing and fever can be symptoms.
-
Tummy bugs: Gastrointestinal infections can cause fever alongside vomiting or diarrhoea.
-
Other infections: Chest infections and urinary tract infections can also cause a high temperature.
Some babies may also develop a mild fever after routine vaccinations. This usually settles fairly quickly.
What is three-day fever (roseola)?
Roseola, sometimes called three-day fever, is a common viral infection that mainly affects babies and toddlers.
It typically causes a sudden high temperature lasting around three to five days, followed by a pink or red rash as the fever begins to settle.
Most children recover without any specific treatment, although it's important to keep them comfortable and well hydrated.
If you're unsure what's causing your child's fever, or you're concerned about their symptoms, contact your GP or NHS 111 for advice.
How do I check my baby's temperature correctly?
The most reliable way to check your baby's temperature at home is with a digital thermometer.
The NHS recommends using a digital thermometer under the armpit for children under 5 years old.
To take your child's temperature:
-
Place the thermometer under their armpit, against their skin.
-
Gently hold their arm against their body.
-
Keep the thermometer in place for the time specified in the instructions.
-
Read the temperature displayed on the screen.
Ear thermometers can also be used, but they may give inaccurate readings in very young babies because their ear canals are so small.
Forehead strip thermometers are less reliable, as they measure skin temperature rather than body temperature.
If your child has just had a bath or has been wrapped up warmly, wait a few minutes before checking their temperature, as this can temporarily affect the reading.
How to help a baby or child with a fever at home
If your child has a fever but is otherwise alert, drinking fluids and responding normally, you can often care for them at home.
The most important thing is to keep your child comfortable, prevent dehydration and monitor their symptoms.
1. Offer plenty of fluids
Babies and children can lose more fluids when they have a fever, particularly if they're sweating.
Offer regular drinks throughout the day. If your baby is breastfed, continue breastfeeding and offer feeds frequently. Formula-fed babies should continue having their usual milk feeds.
For older babies and children, offer water regularly alongside their normal drinks.
2. Let your child rest
Your little one may be more tired than usual when they're unwell. Encourage plenty of rest and quiet activities, but there's no need to keep them in bed if they're feeling well enough to play.
It's also normal for children to have less appetite when they're poorly. Offer food if they want it, but focus on keeping them hydrated.
3. Avoid overheating
When your child has a fever, it's important not to wrap them up in too many layers.
Dress them comfortably for the room temperature and avoid heavy bedding or excessive clothing.
If your baby sleeps in a baby sleeping bag, consider whether their usual clothing and sleeping bag are appropriate for the room temperature and how warm they feel. Avoid adding extra layers simply because they're unwell.
Check your baby's chest or the back of their neck to see how warm they feel. Hands and feet can naturally feel cooler.
The NHS advises against undressing children completely or using cold sponges to bring down a fever.
4. Use fever-reducing medicine if needed
If your child is distressed or uncomfortable, children's paracetamol or ibuprofen may help them feel better.
Always follow the instructions for your child's age and the recommended dosage.
Paracetamol should not normally be given to babies under 2 months old. Ibuprofen should not be given to babies under 3 months or weighing under 5kg, or to children who are dehydrated or have chickenpox. Seek medical advice if your child has asthma before giving ibuprofen.
Do not give aspirin to children under 16, and don't alternate paracetamol and ibuprofen unless advised by a healthcare professional.
Remember, the aim is to help your child feel more comfortable rather than simply bring down the number on the thermometer.
When should I worry about my child's fever?
Most fevers improve within a few days, but there are situations where medical advice is important.
Seek urgent advice from your GP or NHS 111 if:
-
Your baby is under 3 months old with a temperature of 38°C or above.
-
Your baby is aged 3–6 months with a temperature of 39°C or above.
-
Your child's fever lasts for five days or more.
-
Your child shows signs of dehydration, such as fewer wet nappies, sunken eyes or no tears when crying.
-
Your child is not feeding normally, seems unusually sleepy or is not behaving like themselves.
-
You're concerned about their symptoms or their condition is getting worse.
Call 999 or go to A&E immediately if your child:
-
Has difficulty breathing.
-
Has a stiff neck or is unusually sensitive to light.
-
Has a rash that does not fade when pressed with a glass.
-
Is difficult to wake, unresponsive or unusually floppy.
-
Has blue, grey, pale or blotchy skin, lips or tongue.
-
Has a seizure for the first time.
Always trust your instincts. If your child seems seriously unwell, seek medical help, even if their temperature isn't particularly high.
What is a febrile seizure?
A febrile seizure, sometimes called a febrile convulsion, is a seizure that can occur when a young child has a high temperature.
Although they can be frightening to witness, most febrile seizures are brief and do not cause lasting harm.
Febrile seizures are most common in children between 6 months and 6 years old.
What are the signs of a febrile seizure?
During a febrile seizure, your child may:
-
Become stiff or start shaking or jerking.
-
Lose consciousness or become unresponsive.
-
Roll their eyes or appear to stare.
-
Have changes in their breathing or skin colour.
-
Feel sleepy or confused afterwards.
What should I do if my child has a febrile seizure?
If your child has a seizure:
-
Stay with them and note the time the seizure starts.
-
Move any nearby objects that could cause injury.
-
Protect their head with something soft.
-
Do not restrain them or try to stop their movements.
-
Never put anything in their mouth or offer food or drink during the seizure.
-
Once the seizure has stopped, place them on their side in the recovery position.
Call 999 if this is your child's first seizure, if it lasts longer than five minutes, or if they're having difficulty breathing.
Your child should receive medical assessment following a febrile seizure, even if they appear to recover quickly.
Frequently Asked Questions About Fever in Babies and Children
Is 38°C a fever in a baby?
Yes. A temperature of 38°C or above is considered a fever in babies and children. If your baby is under 3 months old, seek urgent medical advice for a temperature of 38°C or higher.
Is 39°C a high temperature for a child?
Yes, 39°C is a high temperature. How concerning it is depends on your child's age, symptoms and general condition. Babies aged 3–6 months with a temperature of 39°C or above need urgent medical advice.
How long does a fever last in children?
Most childhood fevers improve within one to four days. If your child has a fever lasting five days or more, contact your GP or NHS 111 for advice.
Should I wake my baby if they have a fever?
It's important to check on your baby regularly, including during the night. You don't necessarily need to wake them for medication if they're sleeping comfortably, but make sure they're breathing normally and responding as expected. Seek urgent help if they're difficult to wake.
Can teething cause a fever in babies?
Teething may cause mild discomfort and a slight rise in temperature, but a temperature of 38°C or above should not automatically be attributed to teething. Your baby may have an infection or another cause of fever.
What should my baby wear to sleep with a fever?
Dress your baby comfortably for the room temperature and avoid excessive layers or heavy bedding. If they use a baby sleeping bag, make sure it isn't causing them to become too warm. Check their chest or the back of their neck regularly and seek medical advice if you're concerned.
Can a child have a fever without other symptoms?
Yes. Sometimes a high temperature is the first sign of an infection, before other symptoms develop. Keep monitoring your child and seek medical advice if you're worried, particularly if they're very young.
Seeing your baby or child unwell can be worrying, but most childhood fevers are short-lived and improve with rest, fluids and a little extra care.
Keep an eye on how your child is feeling, rather than focusing only on the thermometer reading, and never hesitate to seek medical advice if something doesn't seem right.
Medical disclaimer: This article provides general information for parents and is not a substitute for professional medical advice. Always contact your GP, NHS 111 or emergency services when appropriate.
Source: NHS – High temperature (fever) in children and NHS – Febrile seizures
