The Thermal Earring is a revolutionary wearable gadget developed by researchers at the University of Washington that can continually measure a user's earlobe temperature. In a study with six users, this smart earring—which is intended to serve as both a stylish adornment and a health monitoring tool—showed encouraging results, especially when it came to tracking reproductive health.

"Current wearables like Apple Watch and Fitbit have temperature sensors, but they provide only an average temperature for the day, and their temperature readings from wrists and hands are too noisy to track ovulation," said Shirley (Qiuyue) Xue, who led the study along with Yujia (Nancy) Liu. "So we wanted to explore unique applications for the earring, especially applications that might be attractive to women and anyone who cares about fashion."

Two temperature sensors are included; one dangles in the open below, while the other is magnetically attached to the earlobe. While the latter sensor uses the room temperature as a reference, the former detects the temperature of the earlobe.

The gadget uses a built-in antenna and a Bluetooth Low Energy module to send its readings on a daily basis. In order to conserve energy, it enters sleep mode in between readings. With one charge, the wearable lasts for 28 days thanks to an inbuilt battery.

The earring proved to be more accurate than a smartwatch in taking skin temperature during rest times, according to tests conducted on six volunteers. In addition, it "showed promise" in terms of tracking ovulation and stress in addition to eating and exercising.

The wearer's heart rate and other vital signs may also be monitored by the gadget when it is further developed. It is possible to adorn it with jewels or resin to give the illusion that it is a real piece of jewelry.