Panic button
（重定向自Panic Alarm）
A panic alarm is an electronic device designed to assist in alerting somebody in emergency situations where a threat to persons or property exists.
A panic alarm is frequently but not always controlled by a concealed panic alarm button. These buttons can be connected to a monitoring center or locally via a silent alarm or an audible bell/siren. The alarm can be used to request emergency assistance from local security, police or emergency services. Some systems can also activate closed-circuit television to record or assess the event.