ESI, Section 15 describes the calculation of heated volumes V. Temperature jumps computed from Eq 3 are shown in Figure and overestimate the value of ΔT at all temperatures, reflective of the fact that this represents the maximum achievable T-jump magnitude without considering the weighting of the measured temperature due to the profile of the probe beam, inhomogeneous distribution of the pump energy, or the effect of evolution of the sample heat capacity over the course of the experiment.