Australian workers face more extreme heat every summer, but most workplace heat policies still come down to one temperature and one decision: keep working or stop. This talk will draw on recent human thermal physiology research to show why risk cannot be judged from air temperature alone, and why work rate, clothing, humidity, wind, and sun exposure can shift a safe threshold by several degrees Celsius. It will also set out a practical heat management framework, organised around the hierarchy of controls, so safety leaders can choose evidence-based ways to keep their people cool, productive and safe.