Online, he's heating up is used as shorthand for a sudden run of form, borrowed from sports commentary language where a player on a hot streak is described as heating up. The phrase works in short-form video because it needs no explanation and lands in under two seconds, fitting the fast pace of highlight reels, gaming clips and reaction edits. Creators reuse it whenever momentum shifts, turning an ordinary sequence into a turning point. Its popularity comes from that flexibility, rather than from one specific broadcast or viral moment.