Fire
The book takes its title, Fahrenheit 451, from the temperature at which paper catches fire, a turning point between existing and ceasing to exist.
Montag is also at a turning point. Will he change his life or will he burn under his society’s brutal constrictions?
Fire is a dual element.
A symbol of creation as well as destruction, sometimes both at once, it transforms whatever it comes in contact with.
Fire depends for its identity on who uses it and for what purpose.
Bradbury opens the novel by reversing readers’ traditional expectations of fire.
Instead of a threat from which people must be protected, fire is now a socially sanctioned means of maintaining social order, and firemen are meant to cleanse society of the dangerous influence of books by burning them. Instead of protecting society from fire, they protect society with fire.
But fire can also symbolize knowledge and human connection, light and warmth, as well as creativity.
Late in the book, fire acts as a symbol of emotional warmth and hospitality.
https://www.coursehero.com/lit/Fahrenheit-451/symbols/