The high-mass protostar G358-MM1 underwent an accretion burst in 2019. Such events are rare, and essential to observe in order to test and refine theories of high-mass star formation. During the accretion burst six VLBI observations were made of the 6.7 GHz methanol maser in G358-MM1. The observations traced a 'heat-wave' of accretion energy as it moved through the disk. In this talk I will report the results of the VLBI monitoring campaign and introduce a new, and accidentally discovered, technique called 'heat-wave mapping' which used the accretion burst and multi-epoch VLBI observations to map the spatio-kinematics of the accretion disk at milliarcsecond resolution.