  We discuss the construction of multi-caloron solutions with non-trivial
holonomy, both as approximate superpositions and exact self-dual solutions. The
charge k SU(n) moduli space can be described by kn constituent monopoles. Exact
solutions help us to understand how these constituents can be seen as
independent objects, which seems not possible with the approximate
superposition. An "impurity scattering" calculation provides relatively simple
expressions. Like at zero temperature an explicit parametrization requires
solving a quadratic ADHM constraint, achieved here for a class of axially
symmetric solutions. We will discuss the properties of these exact solutions in
detail, but also demonstrate that interesting results can be obtained without
explicitly solving for the constraint.
