Struggling independent young couple Murphy and Bedelia - he's a lowly clerk, she's pregnant - are two of the more memorable residents of a small town whom the heat is upon, where personal emotions and intensities are rising along with the temperature.
There's dramatically nothing new here, and it isn't new on a TV budget. But in saying that, the TV disaster cycle spawned by the success of the big-screen genre in the 70s was often to be found to be far more briskly entertaining than its bombastic big-budget counterparts. In fact, in Heat Wave! in particular, the tack factor remains pretty low and preposterousness is kept to a minimum, in favour of building tensions amidst characters and their situation.
It's a shame that these films aren't shown TV anymore, as in their way they can be a more thoughtful yet entertaining watch than today's mindless blockbusters, and often at half the length.