This book is dedicated to all the rescuers, the men and women and animals who put their lives on the line daily to save others. To the soldiers, fire fighters, police, EMTs, nurses, doctors, rangers, coast guards, disaster relief workers, rescue dogs, wildland firefighters, ski patrol, and more, I dedicate this book to your bravery and sacrifice. And to the people with no training or super strength who see someone in trouble and step in without reservation to help—thank you for your courage. It gives us all hope for humanity. None of these people would call themselves heroes, but they are. And to some, they are guardian angels.