	Fowler uses the narrator's fever to draw attention to important plot points, but also to introduce an element of ambiguity and uncertainty to the events of the story.
	At each of the three times the narrator suffers from her fever, and important plot point is about to happen. The first time the narrator is afflicted, she is asleep and wakes to the fever. When she recovers she sees that Beverly has left her bed in the night. This moment, while short, is critical to the interpretation of the story, as it introduces the narrator's uncertainty about whether Beverly is happy with Merion or not. When the narrator encounters Merion, she is unsure whether Beverly snuck out to spend the night with him, or with someone else.
The possibility that Beverly is cheating on Merion, as seems to be implied by her night-time disappearance directly following her "whispering" with Wilmet, also draws comparisons between humans and gorillas. 
This draws a clear comparison between gorillas and humans by implying that their attitude towards relationships might be the same. Beverly's ambiguous disappearance allows the author to make this comparison, emphasizing the similarities between species. Without the scene of Beverly's night disappearance, the strength of the author's comparison would be substantially decreased.
	The second time the narrator experiences the fever, she is about to start her conversation with Beverly. This scene begins innocuously, but becomes the pivotal scene of the story, as it is the last time Beverly is ever seen. The narrator repeats several times how much she has thought about and told others about this conversation, emphasizing it's importance.
The narrator's repetition reminds us of the importance of the conversation in finding Beverly. This conversation was important to the plot of the story, but it also significantly impacted the narrator.
The narrator reveals in this reflection just how much Beverly's words, apart from her actual disappearance, have impacted her emotionally. The scene where Beverly last talks to the narrator is important not only to the plot, but also the emotional message of the story.
	The final time the narrator is caught up by fever is when she is about to see the gorillas for the first time. The scene where she encounters gorillas drastically changes the message of the story. When the narrator watches the gorillas, she sees them to be peaceful, herbivorous, and non-aggressive.
The narrator has to see the gorillas for herself in order to decided for herself, without ambiguity, that they are gentle creatures, not fearsome ones. This point becomes especially important when she is finally told by Eddie about what happened after Beverly's disappearance.
Having had her own experience with the gorillas allows the narrator to connect more fully to the horror of the massacre, and to relate that horror to us, the readers. The existence of this scene allows the readers to empathize with the gorillas, which is vital to Fowler's message that humans and gorillas are so similar. Each of the three scenes in which the narrator experiences fever is vital to both the plot and the overall message of the story.
