A lot of that stuff from the 50s was actually pretty good advice. It wouldn't help if you were a mile from the blast, but if you were say 5-10 miles away, you

A lot of that stuff from the 50s was actually pretty good advice. It wouldn't help if you were a mile from the blast, but if you were say 5-10 miles away, you have at least 20 seconds between the flash and when the blast wave hits. There may be glass and debris flying everywhere, and you have a much better chance of survival if you're under a desk with your head covered.