  We consider the spin-1/2 Heisenberg XXZ chain in the regime of large
Ising-like anisotropy $\Delta$. By a combination of duality and Jordan-Wigner
transformations we derive a mapping to weakly interacting spinless fermions,
which represent domain walls between the two degenerate ground states. We
develop a perturbative expansion in $1\Delta$ for the transverse dynamical spin
structure factor at finite temperatures and in an applied transverse magnetic
field. We present a unified description for both the low-energy
temperature-activated response and the temperature evolution of the T=0
two-spinon continuum. We find that the two-spinon continuum narrows in energy
with increasing temperature. At the same time spectral weight is transferred
from the two-spinon continuum to the low energy intraband scattering continuum,
which is strongly peaked around the position of the (single) spinon dispersion
(`Villain mode').
