Imagine you work in a power plant that uses a half dozen massive, 5-story-tall steam boilers. If a cyber attack makes a boiler over-pressurize and explode, the event will most likely kill you and everyone else nearby. Which mitigation for that risk would you prefer? A mechanical over-pressure valve on each boiler where, if the pressure in the boiler gets too high, then the steam forces the valve open, the steam escapes, and the pressure is released? Or a longer password on the computer controlling the boilers? Addressing cyber risks to physical operations takes more than cybersecurity. The engineering profession has managed physical risks and threats to safety and public safety for over a century. Process, automation and network engineering are powerful tools to address OT cyber risks - tools that simply do not exist in the IT domain. This text explores these tools, explores risk and looks at what "due care" means in today's changing cyber threat landscape. Note: Chapters 3-6 of the book Secure Operations Technology are reproduced in this text as Appendix B.