Not a short story but the novel *The Walking Shadow* by Brian Stableford, unless he expanded it from a short story.

While giving a speech to his followers, the protagonist turns into a chrome statue (via some physics process, but from his POV it happens miraculously) and unfreezes in the future.

[![Cover of The Walking Shadow][1]][1]



  [1]: https://i.sstatic.net/DiEUu.jpg