The first rule is to let someone know exactly where you are and how long you expect to be there. Think of this as "filing a flight plan". Make sure that a responsible individual expects to hear from you on or before a specified date, and arrange for a search and rescue expedition to be initiated if they do not.
The second rule is to re-read rule number one.
It is surprisingly easy to get in a great deal of trouble in wilderness recreation areas that are quite close to civilization.
Let's take the labor day weekend, 2010, and an incident that took place involving a veteran police officer, his wife and four children, aged ten through sixteen. He is a close friend of mine.
He decided to take his family kayaking, an activity they had enjoyed before. There were six kayaks in the expedition, all parties had life preservers, and all could swim.
The River they were kayaking down had rapids, but they weren't that bad.
They planned the trip in "leapfrog" fashion, with two cars. One car would be driven downstream and then the other upstream. They would then kayak to the lower car.
The weather was wonderful and the first leg went perfectly. They stopped to picnic.
Then they made a decision to go further downstream and make one more "leg" to end a perfect summer.
The went back to retrieve the first car, drove it downstream and then drove upstream to the point where they had landed.
It was getting late in the afternoon when they started.
Darkness came with unbelievable swiftness.
They found themselves three miles from the destination point when the sun went below the mountains and the river became inky black. They approached rapids, but couldn't see to maneuver. They hit the rocks. All went in the water and lost their kayaks. Four children and two adults. Fortunately they all headed for the same side of the River. Some ended up a ways downstream.
They were in total impenetrable wilderness.
Naturally they had one flashlight, which immediately stopped working.
There was a tiny bar of shale on the River bank. Everywhere else were steep rocky sides.
Somehow they all found their way to this single spot where the walls were not vertical.
Fortunately, one of the children had a cell-phone, which he had double wrapped in plastic. Nobody knew where they were. Nobody knew they went kayaking. Nobody even knew they were on vacation.
They had the number of the local sheriff, who they called (on the cell, which luckily had a signal), assuring him they were alright, but letting him know what happened. They didn't call anyone else, however. They didn't want people to be "alarmed".
They had no shirts, no matches, and fortunately some bottles of water and sandwiches. It was too dark to find wood or construct a shelter. If the weather had been a little colder they would have been in deeper doo-doo.
All huddled together for warmth until the morning came and then waded in shoulder-high water three miles down to the original destination.
The sheriff had done nothing to organize a search or attempt to call them back.
If you are going camping with your family in a wilderness area obtain a United States Coast and Geodetic survey map of the area so you will know the exact grid coordinates. Know if there will be a moon, what the weather is, and the time of sunset.
You don't have to have an elaborate survival kit, but warm clothing, matches, water purification tablets and a cell phone (with a fully charged battery) are a good start. I am tempted to list survival supplies to be carried in a kayak, but there are lots of places that do that.
There is something called judgement. It doesn't weigh very much and costs very little. It should be the first item to consider for four disaster preparedness kit.
And for goodness sake, let someone know where you are and when you are expected to return.