What is normal body temperature for a baby?

A baby's normal body temperature is around 37°C. A temperature above 38°C is considered a mild fever, and a temperature above 39°C is considered a high fever.

Fever can make your baby look unwell, feel hot, uncomfortable and miserable. If your baby is showing signs of a fever, you can take their temperature with a thermometer.

What are the different types of thermometer?

There are several methods of taking a baby’s temperature. The type of thermometer and method used depends on the age of your baby.

Digital thermometers - These can be used in children of any age. They are cheap, easy to use and accurate.

If your baby or child is under 5 years, you can use a digital thermometer under the arm, placing it against their armpit and bringing their arm down over the top of it. Try to keep it in place for at least 2 minutes.

If your child is over 5 years of age, you can use a digital thermometer in the mouth, making sure to place it under the side of the tongue and keeping it in place for at least 2 minutes.

Ear thermometers - These can be used in older children but are not recommended for young babies. They are fast and accurate, but tend to be more expensive than digital thermometers. It is important to be gentle when placing the measuring end of the thermometer into your child’s ear – you don’t have to push it in far.

Infrared forehead and plastic strip thermometers are also available, but they may not be accurate and are best avoided. Mercury-in-glass thermometers are also not recommended as they can be dangerous if broken.

How often should you check your baby's temperature?

When your baby has a fever it’s a good idea to regularly check their temperature and level of discomfort. If your child is content eating, drinking and playing, then it’s just a matter of letting the fever run its course as their body is fighting the infection.

If they are uncomfortable, let them rest as much as possible and encourage them to drink lots of fluids (water or breastmilk) to prevent dehydration. Keeping them in lightweight clothing and bedding is also recommended. If your child is miserable or distressed, you can also give them either paracetamol or ibuprofen. Nurofen for Children contains ibuprofen and is suitable for children over 3 months, and helps to reduce fever for up to 8 hours*. While it’s horrible to see your baby unhappy or uncomfortable, remember that most fevers only last a few days.

Knowing when your baby must see the doctor

Fever is a normal way for your baby to fight an infection but if your baby is under 3 months old, or if they are 3-6 months with a high fever (over 39oC), it’s important to be cautious and always see your doctor. This is because babies are not as good at fighting off infection as older children.

Regardless of the age of your child, seek medical help urgently if they have a very high fever (over 40°C), if they seem to be getting sicker, or if they have a fever along with any of the following symptoms:

  • Uncontrollable shivering or shaking or have chattering teeth
  • Severe headache that doesn’t get better after taking pain relievers
  • Difficulty breathing, or unusual breathing
  • Getting confused, unusually drowsy or you can’t wake them up properly
  • Seem floppy or complain of leg pain
  • Hallucinations
  • Vomiting
  • Stiff neck
  • A worrying rash that doesn’t disappear when you press on it
  • Blue lips and tongue
  • Light is hurting their eyes
  • Refusing to drink
  • Not doing a wee
  • Severe pain
  • An unusual high-pitched cry

If your child has other symptoms as well as fever, such as pain, sore throat or diarrhoea or if you are worried about your child and/or their fever for any reason, be sure to see your doctor.

*Autret-Leca E, et al. 2007.