  We present mid-infrared Spitzer Space Telescope observations of a complete
sample of star-forming dwarf galaxies selected from the KPNO International
Spectroscopic Survey. The galaxies span a wide range in mid-infrared
properties. Contrary to expectations, some of the galaxies emit strongly at 8
micron indicating the presence of hot dust and/or PAHs. The ratio of this
mid-infrared dust emission to the stellar emission is compared with the
galaxies' luminosity, star-formation rate, metallicity, and optical reddening.
We find that the strength of the 8.0 micron dust emission to the stellar
emission ratio is more strongly correlated with the star-formation rate than it
is with the metallicity or the optical reddening in these systems. Nonetheless,
there is a correlation between the 8.0 micron luminosity and metallicity. The
slope of this luminosity-metallicity correlation is shallower than
corresponding ones in the B-band and 3.6 micron. The precise nature of the 8.0
micron emission seen in these galaxies (i.e., PAH versus hot dust or some
combination of the two) will require future study, including deep mid-IR
spectroscopy.
