One of the stories in the collection Daughters of Earth: Feminist Science Fiction in the Twentieth Century (Justine Larbalestier (ed.), 2006) is "The Heat Death of the Universe" (Pamela Zoline, 1967). The story was originally published in a science fiction magazine (New Worlds); and in Daughters of Earth it's followed by an essay that purports to explain why it's science fiction, but I don't really understand the argument there.
Why do (some) people consider this story to be science fiction? (What definition of "science fiction" are they applying?)
(For those who haven't read the story, Wikipedia summarizes it thusly:
"Heat Death" is structured in a loosely encyclopedic style, with 54 numbered paragraphs narrated in a deliberately matter-of-fact third-person voice. It centers on a day in the life of middle-class housewife Sarah Boyle as she goes about preparing her children's breakfast and organizing a birthday party. Boyle's domestic sphere is presented as a possibly closed system analogous to the universe itself, and Boyle as subject to the ravages of literal and metaphorical entropy. As the narrative veers back and forth among scientific explanations, descriptions of household events, and philosophical speculation, the cumulative effect is of a mind and a culture on the verge of collapse.
Edited to add: Since some have questioned my statement that some people consider this story to be science fiction (and the only answer so far basically takes the stance that no one really does), let me elaborate on that a bit.
In Daughters of Earth (which is where I read the story), each story is followed by an essay about it. Conveniently, the essay after "The Heat Death of the Universe" is available online, so you can read it for yourselves; but here are some snippets that show what I'm referring to:
Ketterer’s reading suggests why many women writers have been denied admission to the science fiction camp: woman’s work simply doesn’t merit attention, […]
The debate about whether or not Zoline’s story is science fiction is particularly puzzling in that “Heat Death” is imbued throughout with science fiction thinking.
In other words, the essayist (Mary Papke) not only feels that the story is science fiction, but that it is obviously science fiction, and that people who don't see it as such are apparently male chauvinists.
And it's not just her; the collection's editor, Justine Larbalestier, writes in the introduction (also available online) that:
[…] even sf readers with a less elastic understanding of the field will find that the stories in this collection meet most people’s definitions.
(and lists "Heat Death of the Universe" in the group that "treat directly with scientific theory and practice"), adding that:
Two of the stories have had their science-fictionness questioned: “Heat Death of the Universe” and “What I Didn’t See.” The essays about them by Mary Papke and L. Timmel Duchamp make compelling cases for their inclusion within the genre of science fiction—and more precisely, within feminist science fiction.
(FWIW, I did find Duchamp's case for "What I Didn't See" to be pretty compelling, or at least, it made sense to me. But I couldn't get any purchase on Papke's argument.)