Outdoor-Worker Heat Witness — Design Blueprint: On-Site Temperature and Humidity Sensor with Computed Globe Correction and Safety Margins

DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. Build-ready design blueprint derived from 'A Heat Witness for Outdoor Workers: An Honest Error Bound for Cheap Heat-Stress Estimation' (DOI: 10.5281/zenodo.24108886). Specifies an on-site US$38 temperature and humidity sensor (temperature SD 0.5 C, humidity SD 3 pp) with a computed globe correction (Stull wet bulb, globe elevation capped 2-22 C, solar estimated at 20% SD, wind fixed at 1.5 m/s) implementing WBGT = 0.7 Tw + 0.2 Tg + 0.1 Ta, read with a mandatory 2.0 C safety margin (RMSE 1.05 C, under-reading 0.0097 at the margin). Includes bill of materials (unit costs only where the source states them), siting and computation rules, assembly, installation, calibration and commissioning, operating envelope, maintenance, failure modes and non-claims. Printed failure regimes at full size: free station data requires a 4.6 C margin; the US$120 wearable physiological estimator requires 8.6 C and is not useful as a sole WBGT trigger. All numbers are reproduced by the deposited compute.py.