Analyzing Word Choice in Emotion

Consider the following excerpt from a contemporary novel:

"The city's heartbeat pulsed with an electric fervor, illuminating the shadows where unguarded dreams flickered against the grit of reality."

In this sentence, the author’s choice of the word "fervor" instead of a more common synonym like "intensity" serves to add a specific nuance. What aspect of the city is most directly suggested by the author’s word choice?