Got a Check Engine light today and had two codes, both were IAT Circuit High Input(?, something like that, P113). The sensor is plugged in, so I ran a quick diagnoses and the IAT was reading -38 F, the temps are nowhere near that. Is it possible for the the IAT, the actual black thing inside the tube, to go bad?

Yes the IAT can go bad but it sounds like you have a loose wire. Not sure but think you will have that same code if IAT is unplugged.

The IAT is just an epoxy dipped NTC Thermistor and can be checked with any Ohmmeter.

Disconnect the wiring plug from the IAT sensor and probe the two pins with an ohmmeter.
Good IAT will read between 2000 ohms and 3000 ohms at 70*F.
Resistance will increase as the IAT gets colder.