From ECG to pulse oximetry - diagnostics and monitoring through technical devices have become indispensable in emergency services. However, the more technology is carried on the vehicle, the better rescue personnel must understand its capabilities and limitations. This new guide introduces the correct handling of all common monitoring devices and the proper interpretation of measurement results. Common mistakes and typical diagnostic situations are explained in detail. Particularly, newcomers to the profession will benefit from the numerous illustrations and practical tips. The second edition offers additional case studies that will challenge the reader's diagnostic skills and promise further insights.