Forestry workers play a crucial role in implementing forest management programs, but their outdoor work exposes them to rising temperatures caused by global climate change, which poses potential health risks related to heat. This study focuses on Indonesian forestry workers and examines the relationship between their knowledge of heat-related issues, risk perception, and precautionary behavior in dealing with increasing workplace heat exposure. Developing effective precautionary behavior is essential for preventing heat-related health disorders and promoting health protection programs. To facilitate a comprehensive comparison of the three variables, interviews were conducted with two groups of outdoor workers, comprising 210 forestry workers and 215 paddy farmers. The findings indicate that increasing knowledge about heat-related issues promotes precautionary behavior, and risk perception acts as a mediator between knowledge and behavior. Additionally, the study highlights that the emotion of "dread" intensifies perceived risk and predicts positive behavior change. To enhance heat-related knowledge, exploring the potential use of a "fear" tone is important. In conclusion, comprehensive strategies need to be implemented to promote precautionary behavior among vulnerable forestry workers, particularly manual laborers.