Okay Lily I have a headache but just for you I'll give it a shot.
You can expect that with a title like Fahrenheit 451 there will be a lot of fires. Well, there are. Fire, heat from fire, fiery passion, fiery destruction... I think you get the idea. Fire imagery abounds. Consider what Montag does for a living. He burns books, houses and even ideas (ideas is a more complicated one). He feels passion for the young Clarisse. Really he can't get her out of his mind so I'll call it fiery passion. "Body heat" is the main term here. There is also symbolism of the fiery phoenix rising from the ashes When Granger and Co. pick themselves up after the bombing. The symbolism of fire as life giver and destructor is also at play. At the end of the book it really comes in handy as a source of heat. There is the whole insect symbolism as well. Yucky insects, earphone insects.... I'm not completely clear on this one though , I should look into that more sometime. There is also the "born again naked in the river scene". Montag has his own little baptism as the chase draws to a close. He has shed the old brainwashed subservient Montag for a new improved introspective Montag.