In my test of the Apple Watch Series 8, published on September 15, 2022, I criticized the Apple connected watch for being too cautious in the use of its new temperature sensors. The Californian manufacturer has decided to restrict them to monitoring menstrual cycles, when they can technically do more. I concluded the health part of the test with the following sentence: “After two years of Covid, a watch that could use measurements of heart rate, blood oxygen levels and wrist temperature to detect the onset of illness would have been fantastic.”
Did I play with karma? Three days after writing this test, I tested positive for Covid for the very first time. What motivated me to get tested was precisely my Apple Watch.
Three days of rising temperatures
The new Apple Watch Series 8 has two thermometers. One touches the wrist permanently, the other hides under the screen and is used to calculate the temperature difference with the external environment. This is the first time that Apple has launched a watch with thermometers, while some competing brands, such as Fitbit and Samsung, already do.
Can the new Apple Watch give you your temperature? Unfortunately no. The temperature of the wrist has nothing to do with that of the forehead, which makes the measurement of body temperature very approximate. Some brands have chosen to offer estimates, Apple has chosen to do nothing on behalf of « la science ». In Cupertino at the beginning of September, we were able to discuss with brand managers who told us that they preferred to play it safe. As a result, there is no “Temperature” app on the Apple Watch. Thermometers are only transparently used for ovulation prediction.
To consult the measurements of the “wrist temperature”, it is imperative to use the Health application of the iPhone. This is exactly what I did on Sunday September 18, after having started coughing and blowing my nose two days earlier. I then noticed a significant increase in the temperature of my wrist over the last three days, whereas I had only experienced a feverish episode on the last night. This “disorder” surprised me and prompted me to test myself. And, there, surprise, I was positive for Covid-19.
The days that followed, the fever and the headaches disappeared, which resulted in a return to normal in the application. On Wednesday, I was no longer positive, although I still suffer from some symptoms.
What Apple could do best with its watch
So yes, the title of this article can be misinterpreted. No, the Apple Watch Series 8 does not have the ability to scientifically identify a Covid. On the other hand, she could have suggested that on the second day of my temperature increase, I should take a test, or at least tell me that my body was getting hotter and hotter. Even if it were an option, I would like the option to receive notifications when the Apple Watch detects something surprising in terms of my temperature. This data, combined with data from sleep tracking (which was particularly choppy the days before my test), my heart rate and my blood oxygen level, could probably allow Apple to send good advice to the good time. It’s a shame to have such sensors without any artificial intelligence behind them.
Hopefully watchOS 10 next year adds a lot of new features to Apple’s thermometers. Again, no one is asking Apple to replace antigen testing or real thermometers. Just telling users what the watch sees might be helpful.