According to the latest ‘Power On’ newsletter from Mark Gurman, Apple Watch Series 8 will be able to tell wearers if they have a fever due to a new built-in temperature sensor. Prior to Mark Gurman’s weekend newsletter entry, he tweeted back on January first that he thought that a body temperature sensor would be next for Apple Watch, as noted in the tweet-image below.

Prior to Gurman’s original mention of a temperature sensor in January, Patently Apple posted a patent application on December 30, 2021 titled “Apple invents a Miniature External Temperature Sensing Device for Wearables that estimates subsurface tissue temperatures.” Our cover graphic is from Apple’s patent.

The patent covered Apple’s work on including a temperature sensing device in wearable devices such as an Apple Watch, AirPods, future smartglasses and VR Headset that is configured to estimate subsurface tissue temperatures, heart rate, a barometric pressure, air temperature, moisture level, and so on. Apple described the sensors as being "dual heat flux temperature sensors." For more on this, read our patent report here.

Update 1:20 a.m. July 5: It's being reported today by United Daily News that the company Taiya will be the exclusive  supplier of the new heat sensor chip.