Disaster medicine has occupied an increasingly important niche within the specialty of emergency medicine over the latter half of the 20th century. Regardless of whether an event was natural, anthropogenic, or a combination of both, emergency medicine was and is the ideal discipline to develop the human resources, the strategies, the tactics, and the evidence- based research to elevate the field of disaster medicine. It began, organizationally speaking, with Hurricane Hugo in 1989 and it is continuing through the 2019 COVID- 19 pandemic and beyond.Now that we are well into the 21st century, we must steady our footing as a specialty on the 20th century's foundation so that we can wrestle with the more intricate challenges of the future. In the past two decades our global populations have experienced sectarian violence, wars, genocide, migration, terrorism, emerging infectious diseases, and pandemics. These natural and anthropogenic events will only worsen exponentially as we become intrinsically trapped by the effects of climate change. The United Nation's Intergovernmental Panel on Climate Change has recently concluded that regardless of how we try to reverse the effects of global warming, what we are experiencing now in terms of hurricanes, floods, and droughts will continue to worsen over the next 30 years. Should we, as a species, continue to equivocate and as global temperatures climb, these events will become more frequent and more catastrophic. "Catastrophic" may even be too mild a term. It is possible that over the next few years, the academic arm of emergency medicine may need to consider developing a curriculum devoted to "Cataclysmic Medicine."To confront these possibilities, there first needs to be a knowledge of disaster medicine and disaster management at its most basic level. It begins with crisis leadership, command and control, communications, and coordination. When all these pieces of the jigsaw puzzle are fitted together properly and enclosed by a proper ethical frame, then the best and most ethical and moral disaster medical can will be provided to the patient and to the community.The intent of this book is to introduce these concepts using diverse viewpoints and scenarios. Readers are challenged to cogitate, create, and layer their own set of building blocks upon the preexisting foundation, thereby reinforcing and sustaining their own capacity to prepare for and respond to any adverse eventuality, mass casualty or otherwise. I hope that the experiential and evidence- based contents of this book will inspire readers to delve deeper into the nuances of disaster medicine and will serve as an impetus for a more profound quest for knowledge and a desire to serve those who will be experiencing the worst moments of their lives.The intent of this book is to introduce these concepts using diverse viewpoints and scenarios. Readers are challenged to cogitate, create, and layer their own set of building blocks upon the preexisting foundation, thereby reinforcing and sustaining their own capacity to prepare for and respond to any adverse eventuality, mass casualty or otherwise. It is hoped that the experiential and evidence- based contents of this book will inspire readers to delve deeper into the nuances of disaster medicine and it will serve as an impetus for a more profound quest for knowledge and a desire to serve those who will be experiencing the worst moments of their lives.