  The development of infrared observational facilities has revealed a number of
massive stars in obscured environments throughout the Milky Way and beyond. The
determination of their stellar and wind properties from infrared diagnostics is
thus required to take full advantage of the wealth of observations available in
the near and mid infrared. However, the task is challenging. This session
addressed some of the problems encountered and showed the limitations and
successes of infrared studies of massive stars.
