"Putting on the hotseat" is an idiomatic expression used to describe the act of publicly questioning or interrogating someone. There are a few synonyms to this expression, such as "grilling," which implies a more intense questioning, and "cross-examining," which is often used in legal or courtroom contexts. Another synonym is "interrogating," which suggests a systematic and thorough questioning. "Pressuring" is also a synonym that connotes an attempt to extract information or a confession from the individual being questioned. "Inquiring" is a more neutral synonym, which could refer to either gentle or intense questioning.