Practice safety check
Start a session to create a time-stamped WBGT practice log and receive recurring safety-check reminders.
TAPPS says WBGT should be checked within 15 minutes before practice and, when using an internet-based application or on-site instrument, readings should be taken every 30 minutes during practice. V1.10 defaults to a more frequent 15-minute coach reminder.
Required actions now
—- Waiting for the current WBGT reading.
Football-specific guidance
Measured vs. calculated
FIELD CHECKWhen an on-site meter is entered, the measured value becomes the primary practice reading. The remote calculated estimate is retained only for comparison and calibration.
Current weather inputs
Active sourceAutomatic mode now uses Open-Meteo at the exact selected coordinates for temperature, dew point, humidity, wind, cloud cover, pressure, and solar radiation, then calculates an estimated outdoor WBGT. NWS remains the official cross-check and forecast source. The active source is always shown on the main card.
Accuracy test panel
v1.11 dual-engineCompare both calculation engines against the same reference reading. The current v1.10 engine remains the primary app value; the Liljegren engine is experimental and does not control TAPPS guidance in v1.11.
Experimental engine details will appear after refresh.
Each comparison now saves both the current engine and experimental Liljegren WBGT against the same reference, plus the weather inputs.
Next 8 hours
Holy Cross Heat Safe is still in development. Automatic WBGT values are calculated or retrieved from remote weather information and should be treated as a reference estimate, not a true field reading. Weather can vary across a campus, especially with sun, turf, shade and wind. A calibrated on-site WBGT meter is the preferred source for official field-level decisions.
Practice Log
Current session
No active practiceSaved practices
Logs stay on this device unless you export them. Each check stores the WBGT source, source age, TAPPS zone, weather inputs, and any field-meter value.
Remote/model WBGT is a reference estimate. Use a properly positioned on-site WBGT instrument whenever available and follow the current TAPPS heat policy and your school emergency action plan.
WBGT Forecast
Hourly WBGT values from the NWS forecast grid for the selected location. These values are forecasts, not on-field measurements.
Class 3 Guidance
WBGT is not air temperature or heat index. Holy Cross Heat Safe applies the TAPPS Class 3 thresholds below.
Monitoring timing
- Check WBGT within 15 minutes before practice.
- During practice, TAPPS guidance says readings should be taken every 30 minutes when using an on-site instrument or internet-based application.
- When possible, use the same person for readings and keep practice WBGT records on file.
Holy Cross Heat Safe defaults to a 15-minute reminder, which is more frequent than the 30-minute in-practice interval stated in the TAPPS guidance.
Policy reference
Always use the current TAPPS policy if it is updated after this app version was released.
Open TAPPS Wet Bulb Guidelines ↗Heat Alerts
Browser notification support varies by device. On iPhone, install the PWA to the Home Screen for the best notification support.
Holy Cross Heat Safe does not continuously poll WBGT after the app is fully closed. Reliable background alerts require a push-notification service/backend in a later version.
Settings
15 minutes is the Holy Cross Heat Safe default for more frequent monitoring. TAPPS guidance says readings should be taken every 30 minutes during practice and within 15 minutes before practice.
Primary source: Open-Meteo is called directly from the browser and requires no API key for this prototype. Synoptic remains an optional high-frequency fallback/cross-check. Its token, if used, is stored only in this browser profile.
Heat alerts while app is open
Foreground alerts work while the app is open. Reliable alerts after the app is fully closed require a push-notification backend.
Install on iPhone
- Open the hosted app in Safari.
- Tap Share.
- Choose Add to Home Screen.
- Open Holy Cross Heat Safe from its HC icon.
Data sources
Primary current WBGT: Version 1.11 deliberately keeps the v1.10 calculation as the value that drives the dashboard and TAPPS guidance while calibration continues.
Experimental Liljegren WBGT: The Accuracy Test Panel runs a second heat/mass-transfer calculation using the same Open-Meteo inputs. It estimates natural wet-bulb and black-globe temperatures separately. It is comparison-only in v1.11 and does not override the primary WBGT.
Weather.com: Version 1.11 keeps Weather.com as a manual current-conditions reference and comparison source. The public Weather.com website is not scraped by this app. Automated Weather.com/The Weather Company data would require authorized API access.
Forecast WBGT: NWS raw forecast-grid wetBulbGlobeTemperature layer when available.
Field measurement: an on-site WBGT meter overrides all remote estimates and is the preferred field-level source.
Policy: TAPPS 2026–27 Class 3 WBGT guidance.
Experimental model note: The browser implementation follows the Liljegren/Argonne heat-and-mass-transfer equations, uses the app solar-position calculation, and estimates 2 m wind from Open-Meteo 10 m wind. It is not presented as an on-field measurement or as the exact OSHA calculator implementation.
Holy Cross football field: 29.44, -98.56. Holy Cross Heat Safe is a development/reference tool. Remote weather estimates are not equivalent to a calibrated black-globe measurement made at the field.