This document provides guidelines for work-rest times, fluid intake, and heat category ratings based on the wet bulb globe temperature (WBGT) index to prevent heat injury. It includes: - A table outlining work-rest times and recommended water intake for different heat categories and work intensities to sustain performance and hydration for up to 4 hours. - Notes on factors like shade, body armor, or protective clothing that increase the WBGT and heat stress. - Descriptions of "easy," "moderate," and "hard" work activities to classify the work intensity.