Apple has a related patent from back in 2009. Physical size seems problematic for AirPods when you could use that space for more battery, but I could see this showing up in Power Beats Pro in the not too distant future.

https://www.patentlyapple.com/patently-apple/2009/04/apple-r...

> The sensor can also be other than (or in addition to) an activity sensor, such as a psychological or biometric sensors which could measure temperature, heartbeat, etc. of a user of the monitoring system. Since sensors can be positioned proximate to the head or ear of the user, useful psychological or biometric data can be acquired. The sensor can also be other than (or in addition to) an activity sensor, such as a global positioning system (GPS) receiver or a proximity sensor.

There's enough room to tinker with the dimensions that adding a temperature probe seems feasible. Like the stem of the Pros is actually shorter, which was clever because it means people know you have the fancy new ones. This couldn't add more than a few cubic millimeters.

Breath tracking is pure software, offloaded to the phone, opt-in to auto activate when in exercise mode.

I think we'll see both in the next few iterations, the fitness push is huge and the temperature monitoring would be timely. We'll see.

Even if it's physically possible in the standard AirPods, they might still put it in Power Beats for branding reasons, since those are the more fitness-focused headphones.

Then a year or two down the line, it could make its way down to regular AirPods if the size/cost isn't an issue.