This is a terrific episode, one of the real gems of the original series (despite the slight scientific plot flaw, highlighted by one of the earlier reviewers, regarding what would be required for there to be perpetual daylight. This also leads me to speculate upon what conditions would be like on the side of the Earth condemned to darkness). Again, like one of the other reviewers, I'm something of a fan of these apocalyptic scenarios and this story in particular reminds of the classic film, The Day the Earth Caught Fire (1961), which has a very similar premise. Hey, *what* a coincidence - both were released the same year. How about that? :P Briefly, if you liked this TZ episode, chances are that you'll also appreciate the movie.
P.S. I have to admit that I quite enjoyed watching Lois Nettleton running around in her sweaty shift, too. xD