The thermometer ions were substituted benzylpyridiniums using the survival yield method and MassKinetics. The thermometer ions were diluted in acetonitrile or methanol and a solvent effect was observed for CSI. The internal energies obtained in CSI are 79% and 73% those obtained in ESI with acetonitrile and methanol, respectively, while there is no significant difference between these solvents in ESI. In CSI, ions are cooler when produced from methanol than from acetonitrile. It can be linked to the surface tension (higher for acetonitrile than for methanol), although a larger solvent series would have been necessary to conclude on this. The reasoning is that, during the desolvation process, frictions between the charged droplets and the drying gas induce more heating with acetonitrile. This heating is then converted into thermal energy of the droplets and internal energy of the ions. In summary, in cold spray ionization, the droplets evaporate and disintegrate more slowly. The ions are protected better from collisions at the MS interface better than standard electrospray.