If you or someone in your home is feeling sick, one of the most important things to do before figuring out how to treat symptoms is checking your temperature. “Temperature is an important vital sign that health care providers use to determine severity of illness,” said Dr. Cory Fisher, a family medicine provider with the Cleveland Clinic. “The temperature reading and its duration help to determine potential causes for illness and often will dictate triage and treatment plans.” This is why it’s important to keep a thermometer at home. It can quickly read your temperature, which you can report to your healthcare provider, whether you’re visiting them online or in-person.
Thermometers come in a variety of styles, from under-the-tongue options to those designed with infrared technology. To help determine which thermometer is the best option for you, we talked to medical experts about how to shop for them and highlighted a handful of products that meet doctors’ guidance. We also included expert tips for taking your temperature at home.
How to shop for thermometers
Above all, thermometers should be easy to use and comfortable for those using them, said Dr. Heather Viola, an assistant professor of medicine at Mount Sinai’s Icahn School of Medicine and a primary care physician at Mount Sinai Doctors Ansonia. Because of that, the exact thermometer you buy has a lot to do with personal preference, but experts said to keep the following in mind while shopping.
- Thermometers come in a variety of styles and can measure body temperature in a number of ways, so you should decide which method you’re most comfortable with before shopping. Read more about thermometer types below.
- Thermometers with LCD displays make it easy to see a temperature reading. Viola also recommended looking for options with start buttons that are easy to press so you know the device is on and working when you’re using it.
- Some thermometers beep when they’re done taking a temperature reading, which can be helpful. It takes a few seconds for a thermometer to deliver a reading, and hearing the beep is a good indication that it’s ready to be viewed and interpreted.
Best thermometers to shop in 2023
With doctors’ guidance in mind, we rounded up digital thermometers we think you should know about below. Each thermometer has a digital display, making it easy for you to read results, and we highlighted the method each uses to take a temperature and its power source, as well as other features you may be interested in.
Type: Non-contact infrared forehead thermometer
iHealth’s thermometer is designed with an infrared temperature sensor that the brand says can detect body temperature when it’s held 1.18 inches away from your forehead — this means you can take a temperature without having to physically touch someone. The thermometer takes a temperature reading in one second, iHealth says, and shows the reading on its LED display. When your reading is ready to be viewed, the thermometer vibrates to alert you.
Type: Oral, rectal or underarm
Vicks says its thermometer provides a temperature reading in eight seconds. It’s designed with a digital display that changes color based on its reading to help you understand the meaning of the temperature: A green display means no fever, a yellow display means the temperature is slightly elevated and a red display means a fever is present. The thermometer automatically shuts off after use and its memory settings recalls the last temperature taken if you need to compare them. Vicks’ thermometer comes with batteries and a storage case.
Type: Oral, rectal or armpit
While you can use this thermometer on its own, it also connects to a companion app via Bluetooth, allowing you to keep track of temperatures over time, track medication and set medication reminders and more. The brand says the thermometer delivers a reading in eight seconds or less and displays it on its digital screen. The thermometer also beeps when the temperature reading is complete.
Type: Oral, rectal or underarm
Boncare’s thermometer is the simplest and lowest price option on our list, and it covers all your bases. It delivers a reading in about 10 seconds, the brand says, and displays the temperature on its LCD screen. The thermometer beeps when it’s done taking a reading, has an auto shutoff feature and recalls your last reading to compare temperatures over time.
FridaBaby designed this thermometer specifically for babies if you’re taking a rectal temperature. It delivers a reading in 10 seconds, according to the brand, and displays temperatures on the LED backlit display. The thermometer’s probe is shorter than those on thermometers that are also for oral or armpit use to ensure you don’t insert it too far. Its memory feature stores up to 10 previous readings and it comes with a case for storage.
To help you place Braun’s thermometer in one’s ear, its screen flashes and it emits a beep when it's properly positioned. The thermometer delivers a reading in seconds, the brand says, and you can input the age of the person whose temperature you’re taking. The device’s screen then changes color after a reading based on the age you set to aid your interpretation of the temperature. Braun says the ear probe is pre-warmed for comfort and can be used with disposable lens covers. The thermometer comes with lens covers, a case and batteries.
Type: Forehead or ear
This option can act as a forehead or ear thermometer — it has a built-in infrared sensor you can insert into the ear and comes with a cap you can place on top of the sensor to get a reading from the forehead. The brand says the thermometer delivers a reading in one to three seconds and can recall 20 past temperatures. The thermometer also beeps and displays a red light on its screen when it detects a fever. It comes with a storage pouch and batteries.
Which type of thermometer is the most accurate?
Below, we broke down some of the most common types of thermometers and how each takes a temperature to help you understand the accuracy of readings. We also explained the pros and cons of each one.
Digital thermometers use heat sensors to determine body temperature. They can be used to take a temperature in the mouth, rectum or armpit. Each method of taking a temperature with a digital thermometer can impact accuracy.
Oral: Digital thermometers that take an oral temperature reading have a probe that’s placed under the tongue. Viola said taking an oral temperature is the most accurate way to take the temperature of adults and children 4 years old and above. However, keep in mind that in order to capture an accurate reading, you have to leave the probe under your tongue long enough — the thermometer usually beeps when it’s done taking your temperature. If kids can’t keep the thermometer under their tongue for the full duration of the reading, Viola recommends using another option.
Rectal: Digital thermometers that take a rectal temperaturereadinghave a probe that’s placed inside the rectum, and it’s recommended for infants and children under 3 years old, according to the American Academy of Pediatrics.
Axillary or armpit: Some digital thermometers can be placed under the armpit to measure body temperature. However, Viola told us this method is not as accurate as oral or rectal readings, so it’s best to use it as a quick first check, and you can follow up with an oral or rectal reading if the armpit temperature is above 99 degrees Fahrenheit.
Digital ear thermometers — formally called infrared tympanic thermometers — measure the temperature inside the ear canal using infrared technology, Viola explained. They’re particularly convenient for older babies and children since they usually get you a result in one to three seconds, which is often quicker than oral thermometers. But Viola said ear thermometers can be difficult to position, are usually the most costly option and can give you a cooler reading if the probe tip is cold.
Temporal or forehead thermometers use infrared technology to measure your temperature through the temporal artery on the forehead. Some forehead thermometers are placed directly on the forehead, while non-contact infrared thermometers use infrared technology to measure one’s surface temperature. Both types are generally less reliable and more costly compared to other thermometer options, specifically digital thermometers, Viola said. They can be especially challenging to use with restless children since they have to sit still while the thermometer is getting a reading.
How to clean thermometers
You should always clean thermometers before and after use, experts told us. Viola recommended using rubbing alcohol or soap and water to clean thermometers and storing them in a dry place that is not exposed to drastic changes in temperatures. If you’re using one thermometer as a rectal thermometer, she suggested cleaning it thoroughly and labeling it for that use only.
What is a fever? How can you tell if you have a fever?
A temperature over 100.4 degrees Fahrenheit is considered a fever, Fisher said. And an elevated temperature is a normal part of the immune response — if you have a cold, flu, Covid or other infection, a fever “is likely just a reflection of the immune system doing what it’s built to do: fight off infections,” he explained. But if you have a very high fever (over 104 degrees Fahrenheit) or a prolonged fever (over 4-5 days), Fisher recommends calling your healthcare provider. Additionally, a fever in a newborn baby under 28 days old should always prompt you to call your doctor, he said.
Are thermometers FSA or HSA eligible?
Yes. According to the FSA eligibility list, thermometers are eligible for reimbursement with a flexible spending account (FSA) and health reimbursement account (HRA). However, they’re not eligible with a limited-purpose flexible spending account (LPFSA) or a dependent care flexible spending account (DCFSA).
Meet our experts
At Select, we work with experts who have specialized knowledge and authority based on relevant training and/or experience. We also take steps to ensure that all expert advice and recommendations are made independently and with no undisclosed financial conflicts of interest.
- Dr. Cory Fisher is a family medicine provider with the Cleveland Clinic.
- Dr. Heather Viola is an assistant professor in the Department of Medicine and works as a primary care physician at the Mount Sinai Doctors Ansonia faculty practice. She also serves as the Quality Improvement Champion for Mount Sinai's west side primary care faculty practices. She is involved in teaching and supervising resident physicians and medical students in training at the Icahn School of Medicine at Mount Sinai.