A frontier proposal with a validation plan, not an implemented detector.
Intended capability
Research whether the field could support this proposed outcome: Presence, stillness-duration and man-down alerting in saunas and steam rooms — the exact environments where cameras are prohibited, wearables fail, and collapse goes unnoticed.
This describes the intended outcome. Readiness is research concept, evidence is class C, and a catalog mapping or recording is not proof of this outcome at a real site.
Solution blueprint
See the environment before installing it.
This exact kit is one of 191 first-class designs. It includes geometry, objects, nodes, wording, scenarios, installation, limitations, and catalog-bound readiness.
No rendered revision is available yet.
Bundled recording
A related Hospitality scene
This is one recorded vertical scenario. It is not separate validation of every capability in the catalog.
01 The physics
Heat and humidity are RF-transparent at 2.4GHz (unlike optical/IR); presence, breathing band and the proven fall/stillness compound survive. Hot dense steam adds negligible attenuation at cm wavelengths — the same physics that rejected fire-plume sensing works FOR this product (nothing thermal to see, everything human still visible).
02 Shared processing path
Presence + occupancy count per room -> stillness-duration clock per occupant episode -> man-down compound (high-Doppler transient OR extended stillness beyond policy time + breathing check) -> staff alert with privacy-safe evidence (band timeline, no image).
This is a capability design path. Components may be shared with other catalog entries; it is not presented as a unique algorithm.
03 Validation plan
Own-hardware in one spa: scripted sessions incl. staged lie-downs and policy-time stillness vs staff logs; humidity/temperature cycling across the full sauna range to bound hardware drift (node OUTSIDE the hot room, sensing through the wall).
04 Commercial hypothesis
For the spa operator: 'A welfare check in the one room you cannot put a camera — alerts, not surveillance.'