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Best underarm thermometer

Last Updated: 08.06.23


Underarm thermometers – Buying Guide & Comparison


If you need a non-invasive tool to check whether your little one has a fever or not, you need to get the best underarm thermometer. According to our team of experts, the Hareno Digital Thermometer is a great option if you want a reliable device that provides fast temperature readings. The unit features an automatic shut-off feature if not in use for 10 minutes and the flexible tip on top is comfortable and safe to handle. Thanks to its display you can read the numbers easily and the long battery life ensures you will always have a sturdy thermometer for emergency situations. If the Hareno Digital Thermometer is not available, check the RMS TH-88014 CRAZY Colors Digital Thermometer, another good choice.


Many people feel uncertain about which model to buy and what features make a thermometer a ‘must-have.’ There are several items for sale that comply with the quality standards that are mandatory for the best baby thermometer. In order to lend you a helping hand, we’ve provided you with this useful buying guide showcased below.



One of the most important aspects when in the market for a good underarm thermometer is that you need to get a tool that allows you to know the readings you get are correct. The best way to make sure you’re purchasing a reliable item is to choose one that medical experts agree that you can use for your personal purposes.

Most manufacturers mention in the product description that the temperature readings may vary with a certain number from the accurate level. Ideally, you should get something that allows you to measure within +/- 0.2 degrees of your child’s temperature.

Also, your thermometer should provide realistic readings no matter how many times you use. A stable item will show the same temperature even if you measure it three times in a row. Readings need to provide the same number otherwise the thermometer lacks consistency.


Suitable for babies

Families that have small babies should opt for the best thermometer for babies and adults. Because you want to be able to use it for each member of the family, get a device that is suitable for all ages.

Keep in mind that there are some models manufactures specifically for a baby’s body in order to perform properly while other have different setting according to the age of the person you are doing the temperature reading on.


Pay attention to the features

There are several other features that make a device compatible with you and your family needs. The majority of the underarm thermometers reviews recommend getting a unit that is easy to maneuver.

When in a hurry, you can’t spend precious time trying to figure out how to use the buttons or to interpret the results. Even worse, searching the entire house for the instruction manual. Therefore, you’ll want an underarm thermometer that is simple to use and doesn’t require additional changes, unless if you need to change the batteries.

Also, bulkier devices or the ones that are too fragile to handle don’t make a good purchase if you want to take them with you while traveling. Try to avoid traditional glass and mercury thermometers because they are dangerous and don’t provide accurate readings.

It is a known fact that babies don’t have much patience, so you need to pay attention to the speed. This is valid even for adults because you can’t force them to stay in a certain position until the unit shows you the digits on display. Furthermore, tools that need more than 60 seconds in order to provide the actual body’s temperature tend to be faulty.

Some people like the idea of using a thermometer that has all sorts of buttons and settings, while others desire for something simple that can be activated and deactivated with one simple button.

It’s important to know when you can remove the underarm thermometer away from the body. Models that have a built-in alert that notifies you when the readings are ready is quite useful. However, some parents complain about the noise that wakes up their babies. Keep in mind this and if it’s an issue choose an item that doesn’t feature an alarm.

Most of the time the fever kicks off especially at night, so a display that is outfitted with a backlit s more than practical. This way, you can see the numbers, and you can check your baby without waking him or her up.

Especially underarm thermometers need to have a flexible tip that ensures plenty of comfort and functionality. These products are also suitable for checking the body temperatures in other areas besides the armpit.



5 Best Underarm Thermometers (Reviews) in 2023


We’ve looked at various reports regarding customer and expert reviews as well as sales figures, and managed to create this list of products showcased below.



1. Hareno Digital Thermometer


When facing an emergency situation, it is best to have a reliable thermometer that can be used for checking the body’s temperature for the entire members of the family. Also, a tool that provides fast readings no matter the area you are doing the reading process, is more than practical. This is why this digital thermometer is a great choice for your needs.

Suitable for oral, rectal, and underarm temperature measurements, this device is a perfect alternative to the old thermometers that used mercury in order to provide a correct level of temperature. Moreover, it features a smart automatic usage function that shuts off the device automatically if you don’t test the temperature after a period of 10 minutes.

Due to the incorporated flexible tip, you can rest assured that the thermometer stays in a comfortable position and it doesn’t hurt your little one. The large display allows you to see the numbers without too much effort and there’s no need to replace the batteries often, thanks to the long battery life.



This thermometer can be used for checking the temperature of babies, children, as well as adults, which makes it family friendly.

Plus, this model is easy to use as it comes fitted with a digital display that you will most likely be able to read effortlessly.

It can be utilized for underarm, rectal and oral measurements. Therefore, this is a practical option for those who do not want to invest in more than one thermometer.

The device has a flexible tip that makes it very comfortable, especially when used to take rectal measurements.



There were reviewers who said that this choice is rather pricey considering the minimal features that it comes equipped with. Not many buyers saw this as a major drawback.

Because it runs on batteries, it is advisable that you purchase a few spare ones in case you need them. This aspect does not interfere with the practicality of the thermometer itself.

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2. RMS TH-88014 Crazy Colors Digital Thermometer


If you’re tired of using complicated devices that you can’t use unless you have the instructions with you, then this thermometer will do the trick for you. The product is suitable for babies, children, and adults and can be used for checking the temperature of the body for several purposes such as oral, rectal, and underarm.

This crazy color thermometer is specially designed to deliver accurate and consistent temperature readings within 60 seconds. The accuracy of this device is +/- 0.2 Fahrenheit degrees. Besides, you can toggle between Fahrenheit and Celsius scales, according to your personal preferences.

Quite easy to use, simply take the cover away from the flexible tip and place it under your arm or under the tongue. When the device has done the readings, it will make a beeping sound, so you’ll know that the 60 seconds have passed. The product doesn’t require special handling because it is made from a highly durable material.



One of the first aspects that you are prone to see when it comes to this alternative is its interesting design.

This is a rectal, axillary and oral thermometer and it can be used for babies, adults as well as children.

It can provide its users with fast results. In fact, it only takes 60 seconds for it to deliver a measurement.

To make it as practical as possible the manufacturer has designed it in such a way so that it depicts the temperatures that it reads in both Celsius and Fahrenheit. 



One buyer claimed that he ordered two thermometers and that both of them stopped working accordingly. When this happens, the owners have the right to return the products.

Another customer said that the unit comes supplied with limited features when compared to other similar counterparts. Still, it seems like he was happy with its overall performance.

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3. Kinsa Smartphone Thermometer Old Model


Having a device that you can connect to your smartphone is a great deal since everything that we use nowadays is related to the use of our mobile phone. This special thermometer is easy to handle, and you can pair with your smartphone using the headphone jack. Also, there’s a free app that you install available for download in several mobile apps stores.

The on-screen instructions are quite easy to follow, and the app notifies you when the thermometer is misplaced and can’t provide correct readings. The most important aspect is that this smartphone thermometer offers you consistent and accurate results in no more than 10 seconds.

The tool is intended to be used by the entire family, and it ensures an illness tracking history so you can show to your doctor when the information is required.

Children can be a bit snappy, and it is a tad difficult trying to convince them to stay in place. But this unit benefits from engaging graphics that are appealing to any child.



If you like to make the most of what technology can offer, this product might be just what you need as it has to be connected to the user’s personal smartphone.

The unit includes a history feature that allows owners to look back at previous readings and symptoms.

It can supply buyers with a reading in ten seconds. The model can be used as a rectal, oral and underarm thermometer.

Besides, it is compatible with a long list of smartphones. Before you purchase it, you should make sure that your phone is on the before mentioned list. 



There were reports that claimed that this choice might not be as reliable and accurate as the seller indicates. Not many users agree.

Another customer noted that the device that he was shipped did not calibrate as expected. He was the only one who encountered this issue at the time we checked the reviews of the item.

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4. BCE Qty Digital Fever Thermometers


There are critical situations when you need not one but two reliable thermometers. Especially if you have a large family and more than one child, you’ll know how important is to have a device that provides correct results regarding the body’s temperature.

The product can be used orally, rectally, and for underarm purposes and it is suitable for animal use as well. If you have a dog and you see signs of disease you can use one item from the set for him and the other one for you or your family members.

When you power on the thermometer, you’ll see the previous result, so it is easier to compare it with the new one. This feature comes in handy if you suffer from fever and need to be able to monitor the temperature.

Plus, this tool boasts a long battery life and the batteries used by it are completely mercury free. If you don’t use the thermometer for ten minutes in a row, the automatic shut-off feature will stop the device.



If you decide to get this product, you will receive not just one, but two thermometers that you can use in case of family emergencies when just one device might not be sufficient.

You can utilize the two models to check for underarm, oral and rectal temperatures. It can also be used by vets.

The battery that it uses is prone to last for a long time. The battery can be replaced and it is 100% mercury free for extra safety.

An auto-off feature is also incorporated into its design. This way, in case the model is not used for 10 minutes, it shuts itself off. 



Given the limited features that the choice incorporates, some might argue that this product is a bit expensive.

If one of the thermometers stops working correctly, it might be difficult to say which of the two devices can be trusted. 

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5. Braun PRT1000 High Speed 3-in-1 Thermometer


This premium thermometer is specially developed to measure correctly the level of temperature for any family member, no matter their age. Furthermore, the product is suitable for oral, underarm, and rectal use and you can find detailed instructions in the provided manual.

One feature worth mentioning is the time required for delivering the accurate results, which is only 10 seconds. The ergonomic handle of the tool and the flexible tip ensure a comfortable experience.

As long as you pay attention the notifications regarding the battery level, you can rest assured you’ll always receive accurate and consistent temperature readings.

Due to the easy-to-read LCD display, you’ll see the results fast without having to change the ambient to read the numbers.

If you don’t use the thermometer, after 10 minutes, it will automatically shut-off. Besides, the item is made from waterproof elements so you can easily wash it after each use in order to prevent bacteria spread.



This alternative can supply you with accurate readings in less than 10 seconds and it was constructed in such a way so that contact is reduced.

What is more, this is a versatile model that can be used to measure oral, rectal and underarm temperatures.

The tip of the product is soft, small in size and very flexible so that you will not feel uncomfortable.

The device beeps when the reading is complete so that you know when to take it out. This way, you can minimize any contact time. 



A limited number of previous buyers said that the thermometer that they were shipped did not deliver accurate readings. Most of its users were happy with the results.

When compared to other products that are similar in construction, it becomes clear that this choice is a tad more expensive. Yet, there are content owners that recommend it.

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Ioana Moldovan

Ioana’s professional experience in the optics field has helped her understand the value of passing her knowledge forward. Her curious personality helps her gather useful information for her readers and her goal is to make technical information fun and accessible to everyone.

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