Employees' brain waves are reportedly being monitored in factories, state-owned enterprises, and the military across China.
The technology works by placing wireless sensors in employees' caps or hats which, combined with artificial intelligence algorithms, spot incidents of workplace rage, anxiety, or sadness.
The "emotional surveillance technology" helps employers identify mood shifts so they can change break times, an employee's task, or even send them home.
"When the system issues a warning, the manager asks the worker to take a day off or move to a less critical post. Some jobs require high concentration. There is no room for a mistake."
Another type of sensor, built by technology company Deayea, is reportedly used in the caps of train drivers on the high-speed rail line between Beijing and Shanghai. The sensor can even trigger an alarm if a driver falls asleep.
The technology reportedly increases productivity and profitability, with one company claiming its profits jumped by $315 million.