From wrist to group leader: how a heat alert actually travels

An alert that reaches a dashboard nobody is watching is not an alert. The engineering that matters is not the detection; it is the last hundred metres to a human being who can act.

The chain

• The ring detects a strain trajectory crossing threshold and vibrates on the pilgrim's finger first — the pilgrim always learns before anyone else.
• If not dismissed within sixty seconds, the alert is published to the group's operator queue with the pilgrim's name, photograph and last geofence.
• The duty leader receives a push and an audible tone; if unacknowledged in ninety seconds it escalates to the operations desk.
• At escalation, precise location is released and the family is notified that a check is underway.
• Every step is written to an immutable log the pilgrim can review afterwards.

Designing against alert fatigue

A system that cries wolf is switched off within two days. We tune for a low false-positive rate at the cost of some sensitivity, and we surface a daily digest of near-threshold pilgrims so that a leader can act preventively rather than reactively.

“The best alert is the one that lets someone offer water before anything has happened.”

Last updated 22 February 2026