Seek shelter. If you attended elementary or secondary school during the 1950s and '60s, you will remember air raid drills practiced in the anticipation of nuclear attack. At the teacher's command “duck and cover,” you would stop whatever you were doing, drop down under your desk or against a wall, and assuming a fetal position, interlace the fingers of both hands behind your neck in a “covering” pose. How effective the technique would have been would have depended how far away from the atomic or hydrogen bomb blast's heat, shock waves, and radiation the school was. In any event, defense authorities thought everyone should do something in case of a nuclear attack. In those days, schoolkids did what they were told, so they ducked and covered.