  Using arguments parallel to those used in support of using H2CO as a
sensitive probe of temperature and density in molecular clouds, we measured the
J=7-6 and J=10-9 transitions of thioformaldehyde (H2CS) in several hot core
sources. The goal here was to investigate more closely the conditions giving
rise to H2CS emission in cloud cores containing young stars by modelling
several transitions. The H2CS molecule is a slightly asymmetric rotor, a
heavier analogue to H2CO. As in H2CO, transitions occur closely spaced in
frequency, though they are substantially separated in energy. Transitions of
H2CS originating from the K=0, 1, 2, 3, and 4 ladders in the 230 and 345 GHz
windows can productively be used to constrain densities and temperatures. As a
first step in developing the use of these transitions as thermometers and
densitometers, we surveyed and modeled the emission from well known warm dense
cores.
