A film demonstrating steps to take in the event of a nuclear attack. Animated drawings show the effects of atomic explosions in the air and at ground level. How wide an area is affected by light and heat flash, radiation and radioactive fall-out are clearly illustrated. How to build or improvise a fall-out shelter, what to stock in it, when to take shelter and how long to stay there are similarly explained. Produced by the National Film Board of Canada for Emergency Planning Canada.