It is shown that, by assuming valid a relationship between the work of cavity creation in a liquid and the bulk liquid-vapour surface tension, corrected for curvature effects, and by reproducing calculated Delta G(c) values to create in water and n-hexane a cavity suitable to host a methane molecule, the obtained estimates of the Tolman length prove to markedly depend on temperature, losing a precise physical meaning. (C) 2010 Elsevier B.V. All rights reserved.