Answer:
The temperature increases (gets warmer)
Explanations
When the molecules in a substsnce vibrate faster ans faster, it shows that there is an increase the spaces between the molecules thereby leading to an increase in the kinetic enrgy of the molecule
The presence of this extra spaces causes the molecule to move freely thereby increasing the temperature of the substance.
In summary, the higher the vibration, the higher the kinetic energy, and the higher the temperature.