Apple just patented a sweaty trick every fitness watch could benefit from

A hiking activity on the Apple Watch Ultra 2.

What you need to know

• The U.S. Patent Office granted Apple a patent titled "Wearable Devices with Perspiration Measurement Capabilities."
• The perspiration sensor would measure sweat loss during a workout, both the rate of sweat and total fluid loss.
• Apple would incorporate other sensor data like body temperature and local humidity to help contextualize the data.