The term "hot-button issue" refers to a topic or subject that elicits strong emotions and opinions from people. It is often used in political discourse, social discussions, and public debate. However, there are several other expressions that can be used as synonyms for this phrase. Some possible alternatives include controversial topic, contentious issue, polarizing subject, sensitive matter, volatile theme, and divisive subject. All of these phrases convey the idea that the issue in question is highly charged, and likely to provoke strong reactions from those who are invested in it. Using different terms can help to vary your language and make your writing or speaking more engaging and interesting.