Although laser vaporization of aerosol particles plays an important role in aerosol mass spectrometry, relatively little is known about disposal of excess energy in the degrees of freedom of the gas-phase species. A two-laser scheme, in which an infrared laser vaporizes aerosol particles prior to ionization of the vapor plume by a vacuum-ultraviolet laser, permits the determination of the internal energy of the neutral molecules created in laser vaporization. In this work, the fragmentation patterns of vacuum UV (VUV) photoionization mass spectra of ethylene glycol, in conjunction with photoelectron-photoion coincidence (PEPICO) measurements, determines the internal energy of gas-phase molecules created in the CO2 laser vaporization of neat ethylene glycol particles and ethanol particles mixed with trace ethylene glycol. The internal energy ranges from 1300 to 10250 cm(-1) for CO2 laser powers between 25 and 112 mJ/pulse. For neat ethylene glycol, the rate with which the internal and kinetic energy grows with laser power increases sharply above 65 mJ/pulse, consistent with a change in vaporization mechanism from thermal to explosive. Monitoring the total ion signal as a function of the delay between the CO2 and VUV lasers provides an estimate of the relative kinetic energy of the vaporized molecules. At high laser fluences, the estimated translational energy is greater than the corresponding internal energy, indicative of vibrational cooling in the vapor plume. Ethanol particles containing 1.0% ethylene glycol produce similar results, with the transition in heating rate occurring at a lower temperature. The simplicity of the fragmentation pattern in these spectra and the broad range of temperatures that can be measured in this fashion make ethylene glycol an excellent "chemical thermometer" for reactions initiated by the laser heating of aerosol particles.