Investigating Patient Safety opens with a summary on the main theories representative of human error, such as: "Bad Apples Theory", "Normal Accident Theories" and "High Reliability Organizations Theory". Following this, the authors define mistakes in the diagnostic process, identifying their major causes and suggesting several principles for optimal, bias-free diagnoses. Evidence is presented which supports the idea that the Common Assessment Framework is a total quality management tool that public organizations can use for free for their self-assessment, aiming to improving their administrative capacity and services without having to ask for support from external sources. An analytical exploration of patient advocacy related to patient safety and the concept of a "Theory-Practice-Ethics gap" is presented, reinforcing the importance of their synonymous relationship for trustworthy healthcare practices. The concluding chapter proposes that inline fluid warming devices must employ the safest technology to ensure patients are not exposed to additional risks during the active warming of infused fluids.