In the bow shock model for cometary ultracompact HII regions, a
 stellar wind from a fast moving star interacts with the surrounding
 molecular cloud.  The wind shocks against the ISM and pushes it out
 of the way.  Since the shock velocity is hundreds to thousands of
 kilometers per second, the immediate postshock temperatures are in
 excess of 10^7 K.  This extremely hot gas is in direct thermal contact
 with the very much cooler and denser HII region bounding the wind
 cavity.  A mixing zone or conductive interface exists between the
 two phases.  In either case there is likely to be a substantial
 column density of material whose temperature is near the peak of
 the cooling curve, of order 5x10^5 K.  At this temperature the
 important coronal lines of [FeVII] at 7.81 and 9.51 microns arise
 and we propose attempting their detection with SWS02.

 We expect line strengths as weak as about 1% of the continuum.
 This is a difficult measurement, but we have planned the experiment
 with the view of a 5-sigma detection of a line of this strength,
 paying careful attention to possible systematics in the spectral
 baseline which otherwise would limit us.

 If these lines are found, it will validate the bow shock model for
 cometary ultracompact HII regions.  Additionally it will point to
 these objects as potential laboratories for the study of thermal
 energy transport in extreme conditions where temperature scale
 lengths are small compared to the electron mean free path.