The phrase "warmed a chair" implies that someone did nothing more than sit in a seat without contributing or achieving anything. In contrast, antonyms or opposites for this phrase could include actively engaging in a task or taking responsibility for a project. For instance, "taking the lead," "contributing ideas," "getting things done," or "taking action" could all be antonyms for "warm a chair." These phrases emphasize that individuals are actively participating, taking ownership, and making a difference. By using these antonyms, it encourages people to be more proactive and engaged, rather than just passively occupying a seat.