  We analyze the short-time behavior of the heat and charge currents through
nanoscale conductors exposed to a temperature gradient. To this end, we employ
Luttinger's thermomechanical potential to simulate a sudden change of
temperature at one end of the conductor. We find that the direction of the
charge current through an impurity is initially opposite to the direction of
the charge current in the steady-state limit. Furthermore, we investigate the
transient propagation of energy and particle density driven by a temperature
variation through a conducting nanowire. Interestingly, we find that the
velocity of the wavefronts of, both, the particle and the energy wave have the
same constant value, insensitive to changes in the average electronic density.
In the steady-state regime, we find that, at low temperatures, the local
temperature and potential, as measured by a floating probe lead, exhibit
characteristic oscillations due to quantum interference, with a periodicity
that corresponds to half the Fermi wavelength of the electrons.
