  The properties of high latitude dust are of great interest to extragalactic
astronomers and cosmologists. It is proposed here that essentially all high
Galactic latitude interstellar dust is at a typical temperature of about 20~K
(i.e. it is warm dust) and that if any cold high latitude interstellar dust
exists, its emission at mm-wavelengths is less than 5\%\ of that from the
primary component of warm dust observed by IRAS. Thus the IRAS maps reveal the
high latitude dust of import. The crucial issue is how the emissivity of the
dust scales with wavelength. The mm-wavelength emission in this warm dust only
model is consistent with roughly a wavelength%, $\lambda$, dependent emissivity
$\epsilon(\lambda) \propto \lambda^{-1.5}$. Such a dependence has been observed
in the infrared previously. What is new here is the proposal that this extends
to the mm-wavelength region. Proceedings of Workshop on Molecules, Dust, &
Backgrounds to be published in Planetary & Space Sciences
