From The Treasury of Precious Qualities, Kyabje Kangyur Rinpoche, Jigme Lingpa, and Longchen Yeshe Dorje, pg 392:
As a result of meditation on the mundane level, nonconceptual wisdom will gradually gain in strength, and this will “join” the practitioner to the path of seeing. This phase is therefore called the path of joining and consists of four stages. According to the Mahayana, the first stage of this path, in which the understanding of phenomena as mere mental projections (yid kyi snang ba) acts as an antidote to clinging, is called meditative Warmth.
So on the stage of Heat the understanding of emptiness acts as an antidote to clinging.
_________________Kirt's Tibetan Translation Notes
"Only you can make your mind beautiful."
HH Chetsang Rinpoche