New Apple Watch 8 rumor casts doubt on biggest upgrade

Update: Apple Watch 8 health sensor upgrade ‘is a go’.

Last month Bloomberg's Mark Gurman said that the Apple Watch 8 could feature a body temperature tracker — the first new health sensor for the device since blood oxygen tracking arrived with the Apple Watch 6. 

Now, Apple analyst Ming-Chi Kuo is casting some doubt on the Apple Watch 8 body temperature sensor. It may still be planned for the next-gen Apple Watch launch, Kuo said, but it depends on the company getting the algorithm accurate enough — something Apple struggled with for the Apple Watch 7.

“Apple canceled body temperature measurement for Apple Watch 7 because the algorithm failed to qualify before entering EVT stage last year,” Kuo tweeted. “I believe Apple Watch 8 in 2H22 could take body temperature if the algorithm can meet Apple's high requirements before mass production.”

According to Kuo, the problem isn’t that it’s hard to take a reliable body temperature, but that the wrist where the Apple Watch sits isn’t a place that any physician would pick to take skin temperature, given the choice. 

“The challenge in implementing precise body temperature measurement is that skin temperature quickly varies depending on outside environments,” Kuo continued. “A smartwatch can't support core temperature measurement in terms of hardware, so it needs an excellent algorithm to work together.”

To be clear, Gurman didn’t guarantee that the sensor would be in the Apple Watch 8, and only stated that it could arrive “as early as this year.” All the same, Kuo’s tweets explain the slow progress that wearables manufacturers are making on adding additional health sensors.

Indeed, Kuo adds that Samsung is facing similar difficulties with its rumored temperature sensor. “Unlike previous media reports, I think Samsung Galaxy Watch 5 in 2H22 might not support the body temperature measurement due to algorithm limitations,” he added.

While perhaps not the most compelling smartwatch health sensor (the possibility of an Apple Watch that can measure blood sugar levels has been teased since 2017), skin temperature is a helpful additional metric, if done right. 

According to Gurman, for Apple, the sensor will be primarily used for women’s health features, but as anybody who has had their temperature checked as a COVID-19 screening measure will know, a high temperature can be a sign of illness too. Indeed, both the Fitbit Sense and Fitbit Charge 5 track body temperature overnight to give you a heads up of irregular readings and even the need for more rest.

Some of the best fitness trackers also use temperature as a measure of how ready the body is for exercise, too. Both Whoop 4.0 and Oura Ring Generation 3 use their temperature sensors to inform recovery guidance, with the latter suggesting you take it easy if it spots an unexpected temperature change.   

Whatever Apple has planned for the Apple Watch 8, the company certainly isn’t sitting on its laurels with health sensors. Last year, Apple was revealed to be the biggest customer of Rockley Photonics, which specializes in mobile sensors to measure everything from alcohol to carbon monoxide levels. Body temperature too, just to add a bit more credence to the current discussion. 

Whether any of these make the final cut this time around or not will just have to wait until September, when Apple’s next wearable is expected to debut alongside the iPhone 14.