- Not in effectHeat index below 80°F. Standard EHS practices.
- MonitorHeat index 80–90°F. Begin awareness; provide water and rest.
- In effectHeat index 91–103°F. Implement OSHA heat plan: water, rest, shade, acclimatization.
- High heatHeat index above 103°F or NWS Heat Advisory/Warning. Mandatory rest cycles, buddy system, increased oversight.
Basis & sources
This dashboard is a screening tool for daily EHS planning at STULZ sites in Frederick, MD; Denton, TX; and Dayton, TN. Forecast data is pulled live from the National Weather Service public API for fixed coordinates near each address (no geocoding key required). Heat index is computed from forecast temperature and relative humidity using the NOAA Rothfusz regression.
Status tiers follow OSHA employer heat-index guidance commonly cited for outdoor work (<91°F caution / lower, 91–103°F moderate, >103°F high, with NWS Heat Advisory or Warning bumping a site to High heat). When NWS issues an active alert, the tier shown reflects the alert. Full-sun exposure can add up to 15°F to the perceived heat index — adjust on-site accordingly.
References: OSHA/NIOSH Heat Safety Tool · OSHA Heat Hazard Recognition · NWS Heat Forecast Tools · NWS Heat Index Chart · NWS API
Screening only — not a substitute for on-site WBGT measurement, supervisor judgment, or STULZ site safety policy. Always defer to local conditions.