Prepare for the Worst One of the easiest ways to prepare for an urban emergency is to assemble a 72-hour grab-and-go kit and keep it close at hand. The kit can be very simple or quite complex, depending on how much you're willing to carry. Seasonal changes will require alterations, to handle extremely cold weather, for example. But there are only so many basic categories that need to be covered. Among them are shelter (this includes clothing), drinkable water, food, hygiene, first aid, the ability to build a fire, personal protection, certain tools (such as a knife and flashlight) and communications.