Worried about your baby’s fever?

You’re not alone. A fever is one of the most common concerns parents have when it comes to their children because they know its a sign their baby is fighting something nasty and hate to see our little ones in pain. That’s why it’s so important to have a reliable, accurate thermometer on hand.

In this blog post, I will breakdown all you need to know about baby thermometers as well as how to use them correctly!

Read on to learn more about the different types of baby thermometers and find the perfect one for your needs.

If you want to know about baby room thermometers or baby bath thermometers, you can check out my blogs for those by clicking the links.

How I Choose the Best Baby Thermometers

The hardest part about being a baby is that you can’t communicate (well, that might not be the hardest part. We’ll never know because they can’t tell us). So it’s hard to know if they are healthy and well without some help. If there’s one item that you can’t do without, it’s a thermometer.

You’ll need a lot of thermometers throughout your child’s introduction to the world and it can be difficult to know what types of thermometer to choose, yet alone to then know which is best in each category; a thermometer used for checking body temperature, for example, comes in oral (mouth), axillary (underarm), rectal (rectum), temporal artery (forehead), and tympanic (ear).

Then there’s your budget, with thermometers ranging from £3 to £1760.

That’s before you even think about bath thermometers and room thermometers!

Fret not, I have read through thousands of user reviews and star ratings and spoken to tons of Mums to find the best thermometers for any occasion, and laid them out below with everything you need to know summed into a few sentences so you don’t have to spend hours prowling the internet for the latest information.

Read on to see more about the importance of thermometers for your child's health from Dr Elia Maalouf, consultant pediatrician and neonatologist at the Portland Hospital for Women and Children, the UK’s largest private children’s hospital.

What is a normal forehead temperature for a child?

According to Dr Elia Maalouf, "In order for the body to function efficiently, that temperature must fluctuate within a normal range of 36.5°C to 37.2°C degrees.

"Your child’s body is working all the time to maintain the optimum core temperature. Which all their organs need to function"

Why do babies suddenly get fevers?

Dr Maalouf states, "When an infection invades his body, it mounts what’s called an ‘inflammatory response’ against it. Blood circulation increases around the infected area, carrying the antibodies needed to fight it. This causes his temperature to rise, which also happily kills off some bacteria and viruses that can’t take the heat."

When should you take baby to hospital for fever?

“if your child has a temperature of 39.5°C or above, you should always take action to try to lower it" says Dr Maalouf.

The NHS advises action for newborns under 3months of age with temperatures of 38°C or more or 39°C up to 6 months of age.

How to choose a baby thermometer

When you choose a thermometer for your baby you first need to think about which types is best of the 5 types available.

Lets break it down: oral (mouth), axillary (underarm), rectal (rectum), temporal artery (forehead), and tympanic (ear).

Baby oral thermometers

Baby oral thermometers are more accurate than rectal or axillary thermometers, and they're a lot less scary for kids. Plus, they make it easy to take your child's temperature without disturbing them.

There are a few different types of baby oral thermometers available on the market: a digital or mercury thermometer. Oral thermometers are most accurate in children over 3 and in adults.

Baby underarm thermometers

Digital thermometers work by using heat sensors that determine body temperature so can be used for oral, underarm or rectal temperature readings.

Digital thermometers provide accurate readings in 1 minute or less.

Baby rectal thermometers

Often the same thermometer that can be used to measure underarm, rectal and oral temperatures, however it is extremely important not to actually use the same thermometer for oral and rectal, for hopefully obvious reasons!

The rectal thermometer is considered by many medical professionals to be the gold standard for babies and children.

Baby forehead thermometers

The forehead thermometer is one of the most popular ways to measure skin temperature. It doesn't require any physical contact so can be used out and about and most babies and children take to it easily, unlike underarm (why? just why?!) and rectal (totally get why).

They provide readings in just a few seconds and can be used from newborn all the way to adulthood. The best thing about them is that they can be used while baby is sleeping. However, the reading may not be as accurate as a rectal or ear reading.

Baby ear thermometers

Tympanic thermometers provide fast and accurate readings and come in around the middle on the scare factor with babies and kids.

Tympanic thermometers measure the temperature inside the ear canal through infrared ray technology and for that reason can't be used on babies under 6months old as their ear canals aren't yet large enough to get an accurate reading.

It's also important to to position them correctly and ensure there is no earwax obstructing access.

You will also need to buy a baby bath thermometer and baby room thermometer, you can find all you need to know about those by clicking the links.

Now to the fun part...

So, now you have all the information you need to decide which type of thermometer is best for you and your baby, lets look into the best baby thermometers on the market.

Femometer Digital Thermometer

Best underarm thermometer

Femometer Digital Thermometers

Check Price on Amazon

Why Parents Love It

Parents love that it is easy to use, fast and clinically accurate with high precision. They also say it is great value for money.

What You Need to Know

The thermometer enables 3 precise measurements methods: oral, axillary and rectal. It is waterproof and the clinical thermometer has a memory function the last measurements.

When the measured value is lower than 32 degree, the display shows L; If higher than 42 degree, it shows H.

The thermometer has an automatic shutdown function after 10 minutes.

Vital Baby PROTECT Healthcare Kit for Baby

Best oral thermometer

Vital Baby PROTECT Healthcare Kit for Baby

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Why Parents Love It

Parents love the ease of buying three thermometers in one as well as the cute bear design.

The bath thermometer was a favorite but some parents noted the aspirator was too large for a tiny newborn nose.

What You Need to Know

FLEXISAFE BODY THERMOMETER: Flexible tip makes it safe for oral, under-arm, or rectal use. It also has a smart memory function that keeps track of your baby’s body temperature.

BEAR BATH & ROOM THERMOMETER: suitable for use in both baby’s room and their bath. 100% waterproof. Built-in digital display with an LED light that notifies you if the bath temperature is too high for the baby.

NASAL ASPIRATOR/DECONGESTER: The 100% silicone tip is super soft and helps clear your baby’s nostrils gently, effectively, and quickly

Vicks Rectal Thermometer

Best rectal thermometer

Vicks Baby Rectal Thermometer

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Why Parents Love It

I had to lead with this Amazon review by Michelle Durand….Yeah, you want to use a forehead or ear or basically anything but a butt thermometer. But your pediatrician is going to be fixated on a rectal temp. And frankly, babies are tiny and mysterious and shoving something up their backside when you are stressed and sleep deprived and really you have no idea how far is too far... Yeah, so you want this exact model of thermometer. It is sleep-deprived stressed parent proof to turn off/on and also it's impossible to stick in not far enough or too far.

If that wasn't a high enough recommendation, parents also loved the small tip for use on newborns and that it has been recommended to parents by doctors and hospitals.

What You Need to Know

Requires 1 battery, included and is easy to wipe clean with an alcohol wipe.

Exergen Temporal Artery Thermometer

Best forehead thermometer

Exergen Digital Temporal Artery Thermometer

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Why Parents Love It

Parents love that the thermometer is contactless so you can use on baby while they are sleeping or even running away from you! For that reason its also great for use on the go.

They also love the results coming in a traffic light system and that it is very easy to clean.

What You Need to Know

The Exergen Temporal Artery Thermometer is contactless thermometer with clinical validation and medical certification. This forehead thermometer is reliable for its safety and accuracy with results in less than 1 second.

Using infrared technology, a thermometer can measure the temperature of the forehead. It can also be used to measure the surface temperatures of objects (such as baby's milk) and rooms.

The forehead thermometer has a big LCD screen with 3 backlights and runs off two batteries (included).

Braun Healthcare ThermoScan 7 Ear thermometer

Best ear thermometer used by NHS

Braun Healthcare ThermoScan 7 Ear thermometer

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Why Parents Love It

Parents love that it is simple to use and has an age selection feature to make the reading even more accurate. They said it is easy to select the age and has clear colour coding.

the speed and ease of use makes it easy to use with babies and kids and it works right up to adulthood.

According to a Clinical Investigation Study to validate the age-based Fever Cutoff Points for the AgeSmart feature (Helen of Try proprietary clinical investigation report ref. CR-THR11-01.2018. it is as accurate as a rectal thermometer in newborns

What You Need to Know

Results are available in seconds and it is suitable for all ages from newborn to adult.

Battery level indicator and Ready indicator flashes when the temperature has been recorded.

iProven Oral Thermometer

Best oral and anal thermometer

iProven oral thermometer

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Why Parents Love It

Parents loved the fact the digital display gives a clear fever indication in smileys so they can share the result easily with their kids.

They reported it to be easy to use with fast results.

What You Need to Know

The ProFlex Temp DTR-1221A is waterproof for easy cleaning and comes with a hard case for transporting and require one battery (included).

Do not use for oral AND anal temperature testing, it is better to buy two thermometers.

VAVA Smart Baby Thermometer

Best Smart Baby Thermometer

VAVA Smart Baby Thermometer

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Why Parents Love It

Parents love that this thermometer works remotely so is not intrusive on baby. It works by attaching a stick to baby under their arm and parents have reported this doesn’t seem to bother babies and can last over 24hours.

Its perfect for monitoring temperatures overnight if you suspect your baby may be getting sick or if they have an ongoing condition.

What You Need to Know

Powered by 1 Lithium Polymer battery and has a 24 hour battery life.

Can be used from newborn to adult.


Which thermometer is most accurate for babies?

Rectal thermometers are considered to be the most accurate by doctors for all ages.

If using another type, bear in mind that temperature readings vary, based on how the thermometer is administered:

  • Rectal thermometer readings will be around 0.3°C (0.5°F) to 0.6°C (1°F) higher than oral temperature readings.
  • Tympanic thermometer readings are typically 0.3°C (0.5°F) to 0.6°C (1°F) higher than oral temperature readings.
  • Axillary thermometer readings can be 0.3°C (0.5°F) to 0.6°C (1°F)  lower than oral temperature readings (and may be the least reliable).
  • Temporal thermometer readings are often 0.3°C (0.5°F) to 0.6°C (1°F) lower than oral temperature readings.

Which brand of thermometer is the most accurate?

It depends on the type of thermometer, generally speaking, digital thermometers are more accurate than oral or tympanic thermometers. However, if a digital thermometer is not used correctly, it can be less accurate than an oral or tympanic thermometer.

The best overall brand as voted by healthline.com is CHOOSEEN.

What thermometer is best for newborns?

I know this isn't what parents want to hear but the rectal thermometer is best for newborns as it will provide the most accurate reading without causing possible pain or injury by forcing an ear thermometer on them.

Using a rectal thermometer can be a daunting process so we've broken down here exactly what to do:

-Make sure the thermometer is clean and dry before you use it.

-Lube the tip of the thermometer with a water-based lubricant. You can also use petroleum jelly, but avoid products that contain menthol or alcohol, as they can be irritating to the skin.

-Gently insert the thermometer into the opening of the anus straight in-line with their body, about 1/2-1inch (1.3cm-2.5cm). Try not to push too hard - let the child's body do most of the work.

-Hold it in place for about 5 seconds, then remove it. Read and record the temperature.

What thermometer does NHS use?

One of the thermometers used by the NHS is the Braun Thermoscan 7 Ear Thermometer. It is a clinically accurate infrared ear thermometer that can be used to measure body temperature in both adults and children.

The Braun Thermoscan 7 Ear Thermometer has a number of features that make it an ideal choice for use in clinical settings. These include its fast, one-second measurements, automatic display of results in Fahrenheit or Celsius, and low battery indicator. It is also pediatrician approved and has received the coveted seal of approval from the National Institute of Health.

What is the best way to take a baby's temperature?

While the rectal thermometer may be the most accurate, it's not always practical or the best option depending on other factors such as you're childs age, especially if you're on the go.

For newborns and infants under 3 months old, the best way to take their temperature will always be rectally. This is because young babies' temperatures rise very quickly, and oral or axillary temperatures (taking the temperature in the armpit) can give inaccurate readings.

For infants aged 3-6 months, you can also take their temperature rectally or orally. Rectal temperatures are still the most accurate, but oral temperatures can be used if you don't have a thermometer that can be used rectally.

For children aged 6 months and older, you can also use an axillary.

Are forehead thermometers accurate for babies?

Forehead thermometers are not as accurate as oral or rectal thermometers, but they can be accurate if used correctly.

When taking a temperature with a forehead thermometer, it's important to make sure the sensor is placed in the correct spot on the forehead. The sensor should be placed right against the skin and should not be covered by hair. It's also important to wait at least three minutes for an accurate reading, since a baby's temperature can change rapidly.

If you're unsure about how to use a forehead thermometer or if you're concerned about whether it's giving an accurate reading, it's best to consult with your pediatrician.

Which is more accurate digital or liquid thermometer?

Both a digital thermometer and a liquid thermometer are accurate when used correctly. However, there are some advantages to using a digital thermometer. For one, they are easier to read- just look at the LCD screen.

Secondly, they are faster to respond, meaning you don't have to wait as long for an accurate reading.

Finally, they are often more waterproof than liquid thermometers.

Do you add a degree when taking temp under tongue?

Temperature readings can vary, based on how the thermometer is administered:

  • Rectal thermometer readings will be around 0.3°C (0.5°F) to 0.6°C (1°F) higher than oral temperature readings.
  • Tympanic thermometer readings are typically 0.3°C (0.5°F) to 0.6°C (1°F) higher than oral temperature readings.
  • Axillary thermometer readings can be 0.3°C (0.5°F) to 0.6°C (1°F)  lower than oral temperature readings (and may be the least reliable).
  • Temporal thermometer readings are often 0.3°C (0.5°F) to 0.6°C (1°F) lower than oral temperature readings.

How can I check my baby's temperature without a thermometer?

One way to check your baby's temperature without a thermometer is to take their temperature orally. To do this, wait until your baby is calm and has not just finished eating or drinking. Place the tip of your finger on the roof of your baby's mouth and feel for where their teeth come together. You should press down slightly with your finger until you feel a ridge. Slide your finger along the ridge to the back of their mouth and count how many seconds it takes for your finger to get warm.

Should I let my child sleep with a fever UK?

There's a lot of conflicting information out there on this topic, but the general consensus is that you should let your child sleep with a fever as long as it's not too high (above 39.5°C / 103°F). Fevers are actually beneficial for fighting infection, and can help speed up the healing process.

However, it's important to keep an eye on your child's fever by taking a temperature reading and make sure it doesn't get too high. If your child is uncomfortable or seems to be getting worse, don't hesitate to call your pediatrician.

Should Calpol bring temperature down?

It depends on the source of the fever.

A fever is generally considered a symptom of an underlying illness, and not a disease in and of itself. Therefore, the goal should be to identify and treat the underlying illness, rather than to simply bring down the fever.

However, in general terms, if a person has a fever caused by a viral infection (such as the flu or cold), it is best to let the fever run its course and not try to bring it down with medication. This is because there is evidence that Feverfew - a natural product that reduces fever - may actually hinder the body's ability to fight off the virus.

So, you’ve picked out your favourite thermometer, what’s next?

Ensure you read the instructions for use thoroughly and sterilize the thermometer so its ready to use whenever the occasion arrives.

I hope you’ve found the information above useful, as a first-time parent I often wish I had access to information like this so I want to help other parents through the minefield that is parenthood!

All of the thermometers above are available on Amazon so click ‘Check price on Amazon’ to see which thermometer works best for you and your baby.

Thanks for reading!