The Physical and Chemical Structure of Warm, Dense Regions: IC 63 and IC 443

Elevated temperatures in molecular clouds can result either from heating by ultraviolet photons or from the passage of shock waves. The effect that these processes have on the chemical abundances is not well established observationally, but is of great importance for the interpretation of molecular line observations not only in our own Galaxy, but also in external galaxies. We present here initial results from our study of two "template" regions: the photon-dominated region IC 63 and the shocked region IC 443.