Unreleased Apple Watch body temperature sensor revealed in Apple’s new patent

A new patent for an Apple Watch body temperature sensor suggests that this feature might make its debut in the upcoming Apple Watch Series 8.

Apple Watch Series 7 rating on its side on a white table alongside its packaging
Image: David Švihovec / Unsplash
  • What’s happening? On August 10, 2022, the United States Patent and Trademark Office (USPTO) granted Apple a patent, titled “Temperature gradient sensing in electronic devices” for a body temperature sensor that could be suitable for a small wearable device such as the Apple Watch.
  • Why care? Anything that helps you live a healthier life is worthy of your attention. Being aware of increased body temperature could give you a chance to act sooner before developing illnesses such as COVID-19 or flu.
  • What to do? If your watch is due for an upgrade and you could use some new health sensors, then it’s high time to start saving money for the upcoming Series 8 model, which has been rumored to include body temperature sensing.

Apple Watch body temperature sensor revealed in a patent

The patent text does not specifically mention the Apple Watch as a device suitable for this sensor, but the accompanying drawing clears up any confusion as to the purpose of this sensor. As you can see for yourself above, one of the patent drawings depicts a device resembling an Apple Watch with a dedicated body temperature sensor. Read: Important steps when setting up Apple Watch as new

Patent drawing illustrating how an Apple Watch body temperature sensor works
Image: USPTO

The patent abstract outlines a solution that takes advantage of both a temperature sensor and a differential temperature probe. One end is in contact with the desired surface such as your skin while the other is connected to a temperature sensor which itself is attached to a “back surface such as a back crystal of a smartwatch.“ Apple’s algorithm then calculates the difference between two ends of a probe to derive a differential temperature measurement from it.

Reliable Apple analyst Ming-Chi Kuo has predicted that the upcoming Apple Watch Series 8 models would only offer basic body temperature-sensing functions at launch due to supposed reliability and accuracy issues. That’s because skin temperature can vary wildly depending on ambient conditions.

But if this patent grant is anything to go by, it looks like Apple may have solved those problems—the patent calls Apple’s solution a “high-precision” and “high-accuracy” absolute temperature sensor. The patent was filed on July 21, 2020.

It’s credited to four Apple engineers, among them Chad Bossetti and James Clements. Both men are entrusted with some pretty important roles. Rossetti spent more than seven years in Apple’s Health Technologies group. And his colleague Clements still serves as a mechanical R&D engineering manager with the Health Technologies group. Read: How to watch YouTube on Apple Watch