This publication provides an overview of evidence and guidance on the growing challenge of workplace heat stress in the context of climate change. It highlights the health and productivity risks faced by billions of workers, especially in manual labor sectors. The report details the physiological, socioeconomic, and mental health impacts of heat stress and outlines evidence-based strategies for prevention and mitigation. It emphasizes the need for occupational heat action programmes, stakeholder collaboration, and tailored interventions to protect vulnerable workers, reduce productivity losses, and support sustainable development in a warming world.