It is still a matter for some debate as to how far the most massive stars ever get towards the right-hand side of the HR diagram during the course of their evolution. The apparent absence of very luminous red stars suggests either that stars never reach this region at all, or that if they do, their sojourn there is very brief indeed. If the latter is the case, one might expect to see an increase in mass-loss activity with luminosity among the brightest stars that we actually do see - the cool galactic hypergiants. An attempt has been made to search for one of the signatures of mass-loss - thermal reemission from ejected dust - using recently released data from the InfraRed Astronomical Satellite (IRAS).