General Heat shouldn't be sufficient to degrade water...To separate the hydrogen and oxygen from H20 requires electrolysis...you have two positive hydrogen ions and one negative oxygen ion, it's an electromagnetic attraction between these ions that holds the water molecule together, when electricity is introduced through electrodes, a positive anode and negative cathode, the ions will seek out the opposite charge, so hydrogen, which is positive will collect on the cathode, and oxygen, which is negative will collect on the anode...

To answer the question of "what happens to DMT when vaporized at the perfect temperature?"

...it efficiently becomes DMT vapor.

-eg