  One can obtain very large classes of horizonless microstate geometries
corresponding to near-extremal black holes by placing probe supertubes whose
action has metastable minima inside certain supersymmetric bubbling solutions.
We show that these minima can lower their energy when the bubbles move in
certain directions in the moduli space, which implies that these near-extremal
microstates are in fact unstable once one considers the dynamics of all their
degrees of freedom. The decay of these solutions corresponds to Hawking
radiation, and we compare the emission rate and frequency to those of the
corresponding black hole. Our analysis supports the expectation that generic
non-extremal black holes microstate geometries should be unstable. It also
establishes the existence of a new type of instabilities for antibranes in
highly-warped regions with charge dissolved in fluxes.
