Book excerpt: Disasters strike every day, but despite the best laid plans you may find yourself in one with only the clothes on your back and without a well packed first-aid kit. In Essential Survival Gear, J. Morgan Ayres explains in detail what you need to have when a dire emergency occurs, wherever you are, whoever you are. Ayres—a former Green Beret, martial arts master, and wilderness and urban survivalist—explains his four-layer concept (clothing, day bag, backpack, basic equipment and luxuries) and profiles and provides photos of a broad range of gear, with recommendations on what works best in what scenario—from cityscapes to wilderness and everywhere in between—and how to use it.