Definitely read the actual post, because Nichole explains this concept better than I will. But the gist of it is that characters physical actions can tell us a lot more about their emotions than those worn out descriptions of body parts. She cites a couple of examples from John Greene's YA novel Looking for Alaska, one where MC Miles has to share a bed with the girl he likes, and instead of saying I lay there with my palms sweating and my heart racing and a furious flush creeping to my cheeks, etc., Miles tells us: "We had separate blankets, and there were never fewer than three layers between us, but the possibilities kept me up half the night."
And bam, without any description of what his body parts are up to, we know exactly how Miles must feel. He is lying there under a separate blanket, and he is staying up half the night fantasizing about this girl. His heart, his lungs, his sweat--they're not running the show.
So I'm making that my writer challenge from this point forward, to call myself out on tired body part descriptors and see what my characters can do to let you know how they're feeling. Spoiler alert: the possibilities will probably keep them up the first half of the night, and the violent fucking will keep them up the second.