  The dynamics of the low energy excitations in a ferromagnet is studied in
case a temperature gradient is coupled to the local magnetization. Due to the
different time scales of changing temperature and magnetization it is argued
that only the coupling between the spatially varying part of the temperature
field and the magnetization is relevant. Using variational principles the
evolution equation for the magnetic system is found which is strongly
influenced by the local temperature profile. The system offers damped spin wave
excitations where the strength of damping is determined by the magneto-thermal
coupling. Applying the model to nanowires it is demonstrated that the energy
spectrum is significantly affected by the boundary conditions as well as the
initial temperature distribution. In particular, the coupling between
temperature and magnetization is expected to be several orders stronger for the
open as for the isolated wire.
