Lone worker man-down alarms use motion sensors in a wearable device or phone to detect a fall, or a period with no movement, that could mean the worker is hurt. When triggered, the device first warns the wearer with a sound or vibration and gives a short window to cancel a false alarm. If nobody cancels, it sends an alert with the worker's identity and location to a supervisor or monitoring center. Many devices also have a manual SOS button. Indoors, location comes from an RTLS or beacons; outdoors, it comes from GPS.
The full guide is lone worker safety. Set the no-motion timer to suit the job: tasks with long still periods, such as counting stock or watching a machine, need longer timers or they produce false alarms. Agree who responds, how fast and what they do, and test the whole chain from alarm to arrival on a schedule. Check coverage in cold rooms, mezzanines and yards where signals drop. A man-down alarm only helps after something has happened, so reduce lone work near forklift traffic through scheduling and separation first.