WBGT integrates which factors to assess heat stress at work?

• A. Temperature, Humidity, Radiant Heat, and Air Movement
• B. Wind speed, barometric pressure, UV index, and ozone
• C. Soil moisture, ambient noise, lighting, and air quality
• D. Blood pressure, heart rate, glucose level, and hydration status

Answer: (A)

WBGT is an environmental heat stress index that combines multiple cues that determine how hot it feels and how well the body can cool itself. It uses four interacting factors: air temperature (how hot the air is), humidity (how much moisture is in the air, which affects sweating and evaporation), radiant heat (heat from the sun and surrounding surfaces, captured by the globe temperature), and air movement (wind or ventilation, which influences heat loss through convection and evaporation). By integrating these elements, WBGT provides a single measure that objectively reflects heat stress risk and helps guide safer work practices, such as when to pace work, take breaks, hydrate, or adjust clothing and cooling strategies. Other factors like barometric pressure, UV index, ozone, soil moisture, noise, lighting, or physiological metrics are not direct components of the WBGT calculation, though they can influence safety in other ways.