It was certainly no coincidence that the sultry tale of Tennessee Williams's 1947 A Streetcar Named Desire was filmed in New Orleans. From my personal experience when I visited the city a few years ago, it is certainly hot and humid place. It is no coincidence either that the story transpires in the summer and early fall, which would of course be the hottest time of the year. It is no coincidence because there is a long-standing tradition in the literary and arts world of using heat and fire to symbolize passion. Evidence of this can be found all throughout Elia Kazan's 1951 film version of the movie, adapted for the screen by Oscar Saul.
Stanley Kowalski (played by Marlon Brando) and Blanche DuBois (brought to life on-screen by Vivien Leigh) were the two most "passionate" characters in the movie. It seems that whenever either of them experiences an emotion, it is emotion of the most extreme kind. Appropriately then, when these characters are on screen, there is a lot of heat symbolization used.
One of the first things I noticed is that Vivien Leigh's character smokes cigarettes throughout the film. The most notable aspect of this is that she is always asking someone for a light, so that we see the flame flickering on the screen. It seems that, if she is not lighting a cigarette, then candles are being lit. For whatever purpose, when Leigh is on screen, it seems that there is a flame burning. In addition, Blanche takes hot baths throughout the movie. Sometimes when she emerges from the bathroom, we see the cloud of steam behind her. So even if a flame is not burning, there is still the reference to heat.
With Brando's character, Stanley is usually sweaty. There are several times in the film when he has to change clothes because the t-shirt he has on is wet with sweat. Even in the scenes when he is not sweating quite so profusely, I often noticed a sheen of perspiration on his forehead.
So just as with Leigh's character, whenever Brando's character is on the screen, there is the allusion to heat. The screen heats up even more when the two are shown smoldering together. These two hot-blooded characters transform the movie, but be warned, it is not a movie that is not for the faint of heart.