"On the hot seat" is an expression that means someone is in a position of great scrutiny or pressure. There are a variety of synonyms that can be used to convey the same idea, such as "under fire," "in the spotlight," "on the spot," "under the microscope," "under examination," or "in the hot glare of publicity." Each of these phrases are effective in describing situations where a person is under intense scrutiny or has to answer difficult questions. Regardless of which expression is used, they all share the same meaning of being under intense pressure and in a difficult situation.