Artificial intelligence (AI) and temperature scanners are used in Beijing, China, to screen subway passengers for symptoms of coronavirus. Chinese AI companies Magvii and Baidu have implemented AI-powered scanners across several subway stations to detect passengers' body temperature. The scanners send alerts to company workers if they detect that a person's body temperature indicates a fever. The fever detection system developed by Megvii is said to be able to measure a person's temperature in a crowd at a distance of up to five meters. It can also measure the temperature of up to 15 people per second at one checkpoint. Baidu's system is said to detect the temperature of people on the move, with a margin of error within 0.05 degrees Celsius.