The interest in designing of nanosystems is continuously growing. In engineering many optimization approaches exist to design macroscopic machines. If these methods could be introduced in the nanosystems designing, a great improvement would be obtained in nanotechnologies. But, it is necessary to obtain a link between classical thermodynamics and nanosystems. The aim of this letter is to obtain a first step towards this link. Some considerations on the role of power, time and non equilibrium temperature are discussed and a link between non equilibrium temperature and macroscopic thermodynamic quantities is suggested. This last result opens to new questions. (C) 2015 Elsevier B.V. All rights reserved.