Heat stress forecasts (WBGT) for remote sites

Heat is a daily risk on Australian mine and construction sites through summer. Lumen Sites forecasts heat stress hour by hour for each site, so supervisors can plan the day before it gets hot.

What WBGT is

The wet bulb globe temperature (WBGT) combines air temperature, humidity, sun and wind into one number for heat stress at work. Many workplace heat stress guidelines use it to set work-rest cycles.

How Lumen Sites estimates it

For every hour of the next 48 hours, Lumen Sites estimates WBGT from the forecast temperature and humidity with the Bureau of Meteorology’s simplified method. That method assumes moderate sunshine and light wind, so it can read low in full sun with no breeze and high in shade or a stiff wind.

Each site has a caution level and a stop level, 28 °C and 32 °C by default, which you can change to match your heat stress procedure. The dashboard shades every hour that reaches them and shows the peak for the next 12 hours.

Using it on site

Plan early starts and move heavy work into the cooler hours.
Schedule work-rest cycles and hydration breaks ahead of the hottest part of the day.
Brief crews at pre-start on the hours that will reach your caution and stop levels.

Limits of a forecast

A forecast WBGT is a planning estimate. It does not account for radiant heat from plant and rock, enclosed spaces, workload, clothing or acclimatisation. Measure on site and follow your heat stress procedure.

See Lumen Sites: A$999 a month for up to 5 sites