The recently announced Apple Watch Series 8 can track body temperature due to a new sensor setup inside the smartwatch, but it uses that capability in an interesting way. There are several predictable health benefits one could imagine a temperature tracker would bring, and speculation has run wild for weeks. Apple's eventual decision to use it primarily for a new level of cycle tracking was probably not on anyone's bingo card.

Rumors of a potential Apple Watch temperature sensor initially spread a few weeks ago when the company was granted a patent for "temperature gradient sensing in electronic device." Shortly after that, however, reliable sources began reporting that the next Apple Watch would likely be unable to simply read and reveal a wearer's current body temperature. That information still left ample space for speculation, given the wide variety of use cases for most Apple Watch features.

Related: Apple Watch Series 8 Has Upgrades, But We'll Have To Wait On New Sensors

Based on Apple's recent 'Far Out' event, the new generation of Apple Watch will use temperature sensing to aid the system's cycle tracking. This time, the device will feature enhanced ovulation tracking and can detect abnormalities that might indicate larger health issues. The sensor has two separate components on the watch: one on the side that makes contact with a user's skin and the other just under the display. Apple says this design will lead to more accurate readings that are less impacted by the surrounding environment.

The Science Behind Apple Watch Series 8 Cycle Tracking

Apple Watch Series 8 Temperature Sensors

Adding a temperature sensor doesn't give much meaningful information about a person's cycle on its own, of course. The real magic lies in combining our collective biology knowledge and this new tech. As mentioned during the Apple event, body temperatures become more uniform when a person sleeps because their blood vessels dilate. This makes it possible to achieve an accurate internal temperature reading even near extremities like the wrist (where one might choose to wear a watch).

By combining nightly temperature readings and consistent logging for weeks, people can monitor a process known as the biphasic shift. This process tracks temperature changes related to hormonal shifts and is typically employed to determine ovulation patterns. Since Apple Watch and the Health app handle the data logging, adding consistent temperature readings fits perfectly. It's a convenient way to manage something previously annoying, which is always one of the more noble goals of new tech. In typical Apple fashion, users can access the data on either the Apple Watch Series 8 or an iPhone, and the company stressed that it's private information, encrypted end-to-end.

Source: Apple