What is the relevance of the setting in "Sweat" at the beginning of the story? How relevant is this story in modern times?
The intense heat is relevant to the setting as it shows the escalating rise in temperature for Delia. Delia hears the local men laughing at the way Sykes bets her, takes her money, and cheats on her. She witnesses Sykes and his girlfriend as he buys the mistress expensive things, using the money Delia sweats for.
The physical reaction to intense heat is to sweat, and certainly Delia sweats from both the heat of the day and the exertion of her labors.
It could also be the heat that causes Delia to finally snap. It is intensely hot, and Sykes finally provokes Delia into action. By bringing a snake into the house, something that Delia is frightened of, finally causes Delia to react to all the physical and emotional abuse. Her anger, heated by both temperature and emotion causes her to retaliate.
This is very much relevant in modern society. Heat causes tempers to flair. The physical discomfort causes emotions to be raw. There are many cases of women who finally snap and take action after years of abuse. Television shows, police dramas, and movies on the subject can attest to it.