That depends on the heat generated by the vape. Nicotine has a boiling point of 247 degrees Celsius at which it will evaporate.
Cannabis (when aiming at maximum decarboxylation) and the highest concentration of cannabinoids present, is about 240 degrees Celsius.
Cellulose (tobacco / cannabis plant material) has a burning point of about 290 degrees Celsius. So even at 250 degrees Celsius, it's still far below that point.