Transient absorption data for gold nanoparticles in aqueous solution obtained using a double pump-pulse configuration are presented. The first pulse heats the particles, and the second pulse interrogates the symmetric breathing mode. The experiments were performed as a function of the intensity of the first pulse, and the relative delay between pulses. Analysis of the results show that lattice temperatures of similar to1000 K are achieved at high intensity. This significantly perturbs the surrounding solvent, possibly causing explosive boiling at temperatures greater than 550 +/- 50 K. This threshold is consistent with studies of superheated liquids. (C) 2004 Elsevier B.V. All rights reserved.