"Thin ice" refers to a situation that is unstable or risky, where the potential for failure or danger is high. This metaphor is often used to describe circumstances where one must tread carefully to avoid negative consequences. For example, a person might be on "thin ice" at work if they are underperforming or have received warnings from their supervisor. In a broader context, "thin ice" can apply to various scenarios, such as financial investments or personal relationships. Engaging in risky behavior, like making impulsive decisions, can lead to precarious situations that may result in significant setbacks or harm.