I think that two symbols of the novel can come from the title, itself. The "heat" that is present can be symbolic of the oppressive heat in India or the heat that exists between people in passionate love with one another. Certainly, this is the case for the narrator and Inder Lal and for Olivia with the Nawab. The "dust" there might also be representative of the actual dust from which one can never escape while in India. This dust strikes a foreigner in their travels in India, as it is everywhere and exists in a realm where one is constantly immersed in it. At the same time, the "dust" that surrounds Olivia and the narrator are the elements that help to create challenging situations in their lives, obscuring the exact and reductively clear nature of what needs to be done. One can only sift through the dust, pushing it aside in trying to do what is seen as right and Olivia and the narrator are both a part of this. The letters that Olivia writes are symbolic of her voice being heard. At a time when her voice was effectively silenced by social malignment, the letters operate a way for her voice to be validated and acknowledged, ensuring that the narrator's predicament is also, to an extent, Olivia's, as well.