WBGT measurement requirements on board?

• A. 2 required on board
• B. 1 required
• C. 3 required
• D. 4 required

Answer: (A)

WBGT monitoring on board is about capturing heat stress risk across the actual work environment. Because WBGT is influenced by direct sunlight, shade, humidity, and different work zones, you need two measurements to get a reliable picture of conditions crew members face. With two devices, you can place one in a sun-exposed area and another in a shaded or representative indoor area, ensuring you identify the higher risk and can apply appropriate work-rest schedules and safety measures. It also provides redundancy in case one unit fails. A single measurement may miss hot spots or peak conditions, while more than two isn’t the standard requirement for this purpose.