How to take a baby's temperature

taking baby's temperature

If your baby feels hot or looks flushed, checking his temperature is a good way to determine if he's unwell or simply a bit warm. Knowing how to take an accurate reading will tell you if your baby is running a fever and needs treatment.

What should my baby's temperature be?

The normal, healthy temperature for a baby or child is about 36.4°C but this can vary slightly as all children are different. It's a good idea to take a reading while your baby is feeling well as it will help you gauge what his usual temperature is likely to be.

A temperature over 37.5°C is considered a fever and may indicate that your baby is unwell and needs treatment. Do remember though that a fever in itself isn't necessarily a bad thing. Your baby's temperature will rise when his immune system is busy fighting an infection. So while a high temperature can be a sign of illness, it's also a good sign that your baby's immune system is working just as it should.

Should I call the doctor if my baby has a fever?

You should call your doctor if your baby:

  • is under three months and has a temperature of 38°C or more.
  • is aged three to six months and has a temperature of 39°C or more.
  • is over six months and has a temperature of 40°C or more.
  • has a high temperature that is accompanied by vomiting, a rash or other symptoms.
    h3. When should I take my baby's temperature?

You'll want to take your baby's temperature if you notice signs of a fever such as:

  • Your baby's skin being hot to touch. You'll notice this particularly on his neck, forehead and stomach.
  • His skin feeling clammy and almost sweaty.
  • His cheeks looking red and flushed.
  • Persistent crying for no obvious reason.

What type of baby thermometer should I use?

A baby thermometer can be a useful device to put your mind at rest if you suspect your baby is running a high temperature. You don't need to spend a fortune either with good, reliable thermometers available for under £10, though some go up to as much as £60.

The most popular types of thermometers are digital and take a reading from either your baby's armpit or inside his ear. For children under five, the armpit is considered the best place to take a reading. You can use an under-arm thermometer from birth. It's comfortable for your baby and easier for you to keep him still. The armpit also gives a more accurate reading that reflects your baby's core body temperature.

While some parents swear by a good in-ear thermometer, it can be difficult to keep your baby still and keep the thermometer in place in order to get an accurate reading.

The doctor at the children's ward of my local hospital said the cheap, digital under-arm thermometers are the most accurate and are only around a fiver.

You could also choose an infrared contactless thermometer allowing you to take your baby's temperature without touching him or disturbing him at night. Some digital thermometers even come with a 'smart' function that connects them to an app on your phone allowing you to track your baby's temperature over a period of time.

Look for features such as replaceable covers for the tip of the thermometer and a display backlight. The replaceable covers will ensure the device remains hygienic, particularly important if you use it for more than one child and don't want to risk spreading illness. A display backlight will mean you can read the temperature without turning the light on and waking up your baby. Not every thermometer is suitable for use from birth, so check the product advice before purchasing.

Strip thermometers are held against your baby's forehead to take a reading. They are not recommended so much as they only give the temperature of the skin and not that of the body, so can be misleading.

I have a Vicks Gentle thermometer and it is fab. Every house should have a thermometer.

Glass, mercury thermometers are no longer sold due to safety concerns. There is a risk that the thermometer could break in your baby's mouth causing the mercury to leak. If you already own one of these, chuck it out and treat yourself to a modern one.

Mumsnetters recommend their favourite baby thermometers

baby having temperature taken

“We use a Braun in-ear one. I find it useful to 'chart' the fever to see whether it responds to the medicine.”

“The best one is the £10 digital one from Mothercare. Gives a really good reading in under 30 seconds from the armpit and is really accurate. Stores the last temperature too for comparison. It's been great over the last eight years that I’ve had it.”

“I have a little Peppa pig, under-the-arm one that I got from Asda for £4. When my baby was ill with flu it was pretty accurate and gave the same readings as the hospital in-ear ones!”

Do I need to buy a thermometer?

It isn't a necessity but it is the quickest and most accurate way to take your child's temperature and will give you peace of mind. Some parents prefer to rely on their own instinct to assess if their child is sick rather than use a thermometer, though.

You'll soon become familiar with how your baby's skin should feel and how warm he usually is so you may find that you can tell if your child is unwell just by touch alone. That said, you'll never be able to accurately tell temperature through touch alone so a thermometer can be a useful tool in your parenting kit.

How do I take my baby's temperature?

Firstly, read the manufacturer's instructions. Secondly, consider if there are any factors that might influence getting an accurate reading such as:

  • Clothing or blankets. If your baby has been swaddled in a blanket or has multiple layers on, then this is going to give you a high and inaccurate reading.
  • A warm room. We're all guilty of cranking the heating up during the winter, especially if there's a small baby in the house but if you overheat your baby's room it could be the cause of his high temperature. The temperature of your baby's bedroom should be between 16°C and 20°C. Most baby monitors come with an inbuilt room thermometer. If not you can purchase one separately.
  • A warm bath is will increase his temperature, so avoid taking a reading straight afterwards.
  • If your baby has been active then this will also affect his temperature so don’t take a reading straight after he’s been running around at playgroup.

How do I use a baby thermometer?

child temperature

How you take your baby's temperature will depend on the type of thermometer you use.

  • Under the arm. Hold your baby still on your lap or place him lying down. Turn on the thermometer and check the screen is cleared. Some thermometers hold the last reading taken so make sure the device has been reset before using. Place the thermometer in your baby's armpit against bare skin. You won't get an accurate reading if you try to do this over clothing. Gently hold his arm to his side to keep the thermometer in place. Leave the device there for roughly 15 seconds (although this may vary depending on the product instructions).
  • From inside the ear. If using an in-ear device, you'll have more success if your baby is over three months. Up until that age, you may find that his ear canals are too narrow to be able to properly insert the probe. In-ear thermometers often come with hygienic covers and you should use one of these prior to taking any reading. Place your baby on his side on your lap and aim to keep the thermometer central and pointed towards your baby's ear drum. Hold for 15 seconds until you have your reading.
  • Contactless. Make sure that your baby is not overheated or sweating. Hold the thermometer about 3cm from his forehead and take your reading. Some thermometers will give you a temperature reading, while others will give you an indication in the form of an icon like a happy or sad face.

When using any thermometer, it's good idea to use it on just one part of the body to help prevent any spread of infection or bacteria.

How do I treat a high temperature?

If your baby has a high temperature, there are a few things you can do to help him feel better:
Prevent dehydration by offering lots of feeds to your baby whether you're breastfeeding or bottle feeding him. If you have an older baby that will take water in a bottle or sippy cup, try to offer it to him frequently.
Check on your baby regularly and monitor his temperature. If you notice a spike in temperature, call your doctor
Don't overheat your baby's room or overdress him. Keep his room well aired and don't cover him with blankets or layers.
You could give paracetamol to your baby to help relieve his symptoms. Make sure that you are giving the recommended dose of a medicine that is suitable for your child's age.
*Don't sponge your baby down with cold water. *Cooling your baby too quickly will tell his body that it's cold and needs to warm up, so could actually do more harm than good. Similarly, don't keep his room too cold either.

If your baby is not responding to medicine, his temperature continues to rise or he is showing symptoms of dehydration such as sunken eyes, no tears and no wet nappies, then you should call your doctor immediately.

“Make sure your little one has access to water at all times and really push the drinking, even throughout the night. Dehydration can be a serious complication, so just monitor the wet nappies. Dress him in a nappy and have a thin blanket for when the temperature reduces.”