Dark matter can't radiate heat (i.e. no electromagnetic energy). 1. Might it retain the original temperature at the moment of its creation? 2. If temperature is directly related to pressure and both are inversely related to volume, then would cosmic expansion mean that dark matter is as cool as the cosmic microwave background radiation? 3. Can the temperature of a given region of dark matter be inferred based its inferred volume and mass? 4. Does the inability of dark matter to radiate heat imply that there can be no dark matter "black holes"?