Student populations in higher education are more diverse than ever before. Studies of classroom engagement have repeatedly shown that instructors act on implicit biases and that classroom participation is rarely equitable. What can instructors do to support diverse students, specifically with regard to managing classroom engagement and facilitating equitable participation? The practice of cold-calling--calling on a student who has not volunteered to contribute a response--has previously been suggested to support a number of desirable classroom outcomes. However, cold-calling is increasingly recognized to be a potential source of significant student anxiety, particularly for students already experiencing heightened stress due to stereotype threat or other barriers to learning. As such, the solicitation of random and immediate feedback may actually exacerbate inequities rather than ameliorate them as intended. Here, we introduce a novel classroom participation approach that we call the warm call. This engagement method provides students with an advance warning, and the opportunity to opt out of sharing in front of the class. We describe two different approaches--the "in-class warm call" and the "before-class warm call"--which can be utilized by instructors in any level or size of class to support equitable student participation while also respecting student autonomy.