  We review present understanding of Galactic free-free emission and its
possible importance to CMB fluctuation measurements. Current results, from both
``direct'' observations in the microwave band and from H$\alpha$ studies,
suggest that this foreground does not represent a serious obstacle to mapping
the CMB; however, this is based on limited information and we emphasize the
need for more exhaustive studies. We also present some preliminary results
based on our recent H$\alpha$ observations near the South Pole CMB data sets.
The fluctuation amplitude seen in H$\alpha$ indicates that the detected CMB
fluctuations are not significantly contaminated by free-free emission, at least
if the diffuse gas is at a temperature of $T\sim 10^4$ K.
