Were we ever this paranoid? Yes. And "duck and cover" would've been about as useful during a nucelar attack as any of these suggestions are for a biological or chemical attack.
I remember as a kid in the '60s I knew some guys who had bomb shelters in the backyard. By 1970 though, they were pretty much gone, they were shabby, filled with water and everyone knew that the basement of every McDonalds was a bomb shelter
When I was in HS,a buddy and I filmed some horror movie scenes in our school's bomb shelter(when we weren't getting high in it ).I never did see the whole of the damn place.It was huge... Long way of saying yes....