  We study the IR emission from flared disks with and without additional
optically thin halos. Flux calculations of a flared disk in vacuum can be
considered a special case of the more general family of models in which the
disk is imbedded in an optically thin halo. In the absence of such halo, flux
measurements can never rule out its existence because the disk flaring surface
defines a mathematically equivalent halo that produces the exact same flux at
all IR wavelengths. When a flared disk with height H at its outer radius R is
imbedded in a halo whose optical depth at visual wavelengths is \tau\sub{halo},
the system IR flux is dominated by the halo whenever \tau\sub{halo} > (1/4)H/R.
Even when its optical depth is much smaller, the halo can still have a
significant effect on the disk temperature profile. Imaging is the only way to
rule out the existence of a potential halo, and we identify a decisive test
that extracts a signature unique to flared disks from imaging observations.
