The use of waste heat from industrial processes has significant, yet underutilized potential for increasing energy efficiency. This work contributes to the heat transition. The focus of the book is on the utilization of waste heat in the industry, specifically in the medium to low temperature range up to 600 degrees Celsius. Energy-intensive industrial sectors such as steel, glass, cement, and food can benefit from the latest research findings on energy efficiency in the collaboration between academia and industry. The authors provide valuable insights for practical implementation in their respective sectors as well as cross-industry benchmarking. Key topics include: fundamentals of waste heat utilization, characteristics of waste heat streams, technologies (heat transfer, transformers), methods for identification and optimization, integration of systems, and potential.