---
title: "What Is WBGT? Heat Stress and Hydration Glossary"
description: "Wet bulb globe temperature (WBGT) combines temperature, humidity, sunlight and air movement into one heat stress reading."
url: https://jmarsolutions.multisites.ai/glossary/wbgt
publisher: JMAR Solutions
phone: +1-214-632-7780
quote: https://jmarsolutions.multisites.ai/contact
---

Measurement

# WBGT

Wet bulb globe temperature (WBGT) combines temperature, humidity, sunlight and air movement into one heat stress reading. OSHA uses it to decide if a heat hazard existed.

WBGT stands for wet bulb globe temperature. It blends temperature, humidity, sunlight and air movement into one number. NWS calls it a particularly effective indicator of heat stress for outdoor workers and athletes.

OSHA calls an on-site WBGT meter the most accurate way to measure how environmental heat affects body temperature. OSHA's Technical Manual says OSHA uses WBGT to decide if a heat hazard was present. Many crews still use the [heat index](https://jmarsolutions.multisites.ai/glossary/heat-index) because it needs only a forecast. WBGT needs a meter, but it counts sun and wind. Learn when to use each in our [WBGT vs heat index guide](https://jmarsolutions.multisites.ai/guides/wbgt-vs-heat-index). Both feed a [work/rest schedule](https://jmarsolutions.multisites.ai/glossary/work-rest-schedule).

[From JMAR SolutionsHydration programs and toolbox talks for crews](https://jmarsolutions.multisites.ai/hydration-programs)

## Related terms

-   [Heat index](https://jmarsolutions.multisites.ai/glossary/heat-index)
-   [HeatRisk](https://jmarsolutions.multisites.ai/glossary/heatrisk)
-   [Work/rest schedule](https://jmarsolutions.multisites.ai/glossary/work-rest-schedule)
-   [Heat index work rest chart](https://jmarsolutions.multisites.ai/glossary/heat-index-work-rest-chart)

## Sources

1.  [NWS: Heat Forecast Tools](https://www.weather.gov/safety/heat-tools)
2.  [OSHA: Heat Overview](https://www.osha.gov/heat-exposure)
3.  [OSHA: Heat Overview](https://www.osha.gov/heat-exposure)

![Ironworkers silhouetted on a steel frame against a hot orange sunset](https://jmarsolutions.multisites.ai/_astro/sunset-steel.IhAMDca0_6wk53.webp)

## See it on your crew in 15 minutes

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