7 best thermometers for kids and adults
Doctors recommend keeping a thermometer at home in case someone feels sick, and buying digital options that are easy to read.
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.
Type: Rectal
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.
Type: Ear
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.
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.
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.
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.
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).
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.
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