I only recently notice hellish symbolism towards the end of the film
Having seen the movie hundreds of times, one thing I have failed to notice until now is that when they go down to the generator room, the movie does a classic theme that a lot of movies have done: Descending into hell. For the climax of the third act of a film, sometimes the movie tones down the light, oftentimes utilizing a lot of red lighting representing going through the realm of hell or the underworld for the final battle. This of course is done on purpose. Good movie makers set these kinds of things up because whether or not we understand the hidden language of their film making, our subconsciousness have the intended reaction to what we're seeing. I started watching the Michael Jackson biopic yesterday, "Michael", and I immediately picked up on three clever things the director did. When Michael has his first plastic surgery and is all taped up, his father who is in the process of shaving with a straight razor calls him over to check on him. At the end of the talk he flicks the razor around a little through the air and closes the door, the razor thematically tying into and foreshadowing Michael's future plastic surgery. In one scene where Michael does a subtle stand against his father by getting a baby chimpanzee, he tells his father something of double meaning. The mother had said the chimpanzee is a wild animal, Michael says that no, he is sweet. If a chimpanzee is threatened it either hides or attacks. And Michael looks at his father, the meaning is quite clear! And later Michael is petting a snake, a big boa constrictor or something similar. Michael's brother tells him his father is calling him over for a meeting. Michael tells his girlfriend that the snake is getting hungry and wants to eat something big, maybe a mouse. His father being the snake in this metaphorical filmmaking. I really like these little clever tie ins that movie do. And in The Thing, the reddish hell Mac, Gary and Nauls steps down into is almost like a hell that has frozen over.