This United States Army medical manual, Technical Bulletin, Medical TB MED 507 Heat Stress Control and Heat Casualty Management April 2022, provides guidance to U.S. and allied military and civilian leaders, safety and occupational health professionals, unit safety officers, and healthcare providers to: Develop an evidence-based preventive program to protect military personnel from heat stress and associated adverse health effects. Understand the diagnosis and treatment of exertional heat illnesses including heat exhaustion (HE), exertional heat injury (EHI), and exertional heat stroke (EHS). Understand the physiological responses and adaptations to heat stress (chapter 2). Implement procedures for managing heat stress (chapter 3). Understand the epidemiology and pathophysiology of exertional heat illnesses (chapter 4). Implement treatments for exertional heat illness (chapter 5). Understand the effect of fluid and electrolyte imbalances (chapter 3). Understand the proper use and interpretation of the wet bulb globe temperature (WBGT) index as it relates to work-rest cycles (chapters 2 and 3). Mitigate exertional heat illness during training and deployment (appendix C). Provide background information for reporting and data collection of epidemiological information to note trends and to identify individual, work, and environmental factors that are not adequately controlled by preventive measures and policies (chapter 5).