Human body temperature is a vital sign. It is used to assess the state of the body at any given time. And while Google claims the average body temperature is 37 degrees Celsius, the truth is that it is range. The range is from 36.6 degrees Celsius (97.9 degrees Fahrenheit) to 37.2 degrees Celsius (99 degrees Fahrenheit). 

In many disease conditions, a raised temperature is the first sign of illness. This was evident globally with the use of thermometers to screen people for possible COVID-19 infection. 

The conventional device for measuring body temperature is the thermometer. Numerous types of thermometers and even smart ones are available in the market today. They  include: 

  • mercury thermometer
  • pacifier thermometer
  • digital thermometer
  • electronic ear thermometer
  • Oral thermometer 

With advances in technology, wearable temperature sensors are now embedded into several smart devices (cloth, watch, phone, etc.) to measure the body’s temperature as the device is worn. Wearable temperature sensors have the advantage of being optimized for remote monitoring.

They can transmit their findings to a hospital, allowing the hospitals to continue monitoring patients at home, thereby reducing hospital stay. But how accurate are these devices? Do smartwatches have the potential to replace thermometers? To answer these questions, we will review the options and their effectiveness in measuring body temperature.

What are the options for measuring temperature with a smartwatch?

When smartwatches are embedded with a wearable sensor, they become enabled to measure body temperature. One primary reason smartwatches are not considered ideal for measuring temperature is the effect of factors like sweat, stress, and other external oscillating factors that make a smartwatch’s skin temperature readings differ from the actual body temperature.

Below are some of the smartwatches that will not replace an old fashion bucal thermometer but will somehow be useful in analyzing the skin temperature.

Ticwatch GTH

TicWatch GTH by Mobvoi

4.5 stars

Price when reviewed: $79.99

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The Ticwatch GTH was launched in 2020 and offers the ability to measure body temperature. The accuracy of its readings is placed at 0.1 degrees. It doesn’t serve a diagnostic purpose, but it gives relatively accurate information on the body temperature state.

It takes only a few seconds for this watch to measure your temperature on demand. Beyond its temperature measuring function, Ticwatch has other amazing features like the ability to check blood oxygen saturation level, respiratory rate, and more. It comes with a powerful battery (more than a week) and is compatible with Android and iOS devices.

Amazfit GTR 2e

GTR 2e by Amazfit

4.5 stars

Price when reviewed: $124.99

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Also launched in 2020, this smartwatch continuously measures skin temperature. It also has an excellent battery life (up to three weeks while in basic mode). However, this device lacks automated temperature tracking and does not establish a normal baseline. Some users also noted that its temperature readings seemed lower than the expected normal. 

Fitbit Sense

Sense by Fitbit

4.5 stars

Price when reviewed: $248.95

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The Fitbit Sense made its debut in 2020 as well. It adopts a different approach to temperature tracking. Instead of the temperature on-demand style, the Fitbit Sense tracks temperature at night and displays any deviation from the baseline temperature in a daily graph. The baseline is determined after logging up three nights of sleep on the device. It is believed to be a valuable complement for those tracking temperatures for fertility or feminine hygiene purposes. 

Ava

Ava-fertility-tracker-1

Ava by Ava Science

4.5 stars

Price when reviewed: $259.00

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Ava is not a smartwatch in the strict sense of the word.  It is a wearable device that replaces thermometers as the tool of choice for monitoring fertility-related temperature changes. Launched in 2016, its makers claimed it is an accurate predictor of fertile days. However, its temperature detection abilities have not been proven to be as good as a regular thermometer mainly because it measures surface temperature directly. Interestingly, Ava was recently proven to diagnose COVID-19 with an accuracy of 71%.

Can smartwatches replace thermometers?

The ability of smartwatches to measure core body temperature is still limited. They can measure the skin temperature at the moment, and their readings are affected by many external factors. However, wearable temperature sensors are expected to measure body temperature more accurately and continuously in the near future as the technology improves. 

Until smartwatches can measure core body temperature reliably and continuously, they will still not replace thermometers but are a step in the direction of a ubiquitous health device.

What does this mean for you? 

A smartwatch reading can be used as a loose indicator of your actual body temperature. If you notice a rise or a spike, then using a regular thermometer to get an accurate reading is advised.

Smartwatches should not be used for temperature readings that involve disease management or critical care. They can only serve as a guide and a marker of what your normal body temperature range is.