1. When you hear the warning signals, or warning information is broadcast, take prompt action. 2. If the Attack Warning Signal sounds, go to a fallout shelter immediately (unless your local government has told you to do something else). After you are in shelter, listen to a radio for more information and instructions. 3. If there is no public or private shelter you can go to, try to improvise some fallout protection. As a last resort, take cover in the best available place. 4. If there should be a nuclear flash--especially if you feel the warmth from it--take cover _instantly_, and then move to a fallout shelter later. KNOW ABOUT WARNING An enemy attack on the United States probably would be preceded by a period of international tension or crisis. This crisis period would help alert all citizens to the _possibility_ of attack. If an attack actually occurs, it is almost certain that incoming enemy planes and missiles would be detected by our networks of warning stations in time for citizens to get into shelters or at least take cover. This warning time might be as little as 5-15 minutes in some locations, or as much as an hour or more in others. How you received warning of an attack would depend on where you happened to be at that time. You might hear the warning given on radio or television, or even by word-of-mouth. Or your first notice of attack might come from the outdoor warning system in your own city, town or village. Many U.S. cities and towns have outdoor warning systems, using sirens, whistles, horns or bells. Although they have been installed mainly to warn citizens of enemy attack, some local governments also use them in connection with natural disasters and other peacetime catastrophes. Different cities and towns are using their outdoor warning systems in different ways. Most local governments, however, have decided to use a certain signal to warn people of an enemy attack, and a different signal to notify them of a peacetime disaster. THE STANDARD WARNING SIGNALS The two "standard" signals that have been adopted in _most_ communities are these: THE ATTACK WARNING SIGNAL. This will be sounded only in case of enemy attack. The signal itself is a 3- to 5-minute _wavering sound_ on the sirens, or a _series of short blasts_ on whistles, horns or other devices, repeated as deemed necessary. The Attack Warning Signal means that an actual enemy attack against the United States has been detected, and that protective action should be taken immediately. This signal has no other meaning, and will be used for no other purpose.