What are the identification principles or precautions of thermal radiation in occupational health, and what is the temperature?

In occupational health, as long as there is a fixed heat source on site, which may continuously emit heat, or there is open-air operation in summer, it is necessary to carry out high temperature detection. Now in the new occupational health standard, there is no radiant heat, and the WBGT index is used. As long as the WBGT index is greater than 25 degrees Celsius, it is considered as high temperature operation. See the provisions of GBZ/T 189.7-2007 for specific detection methods.