We are currently revamping the heat equation solver we developed for lava flows so that it can be integrated in the main GPUSPH branches. Although it is unlikely that this will be integrated in GPUSPHv6, the feature should become available on the next branch after the release of GPUSPHv6 is finalized.
(For the curious: the release of GPUSPH v6 is currently stalled, pending the publication of two manuscripts on some of the most significant improvements to the model and its implementation.)