Okay so if raising the temperature of a substance increases the movement of the molecules, then increasing the movement of the molecules would also increase the temperature. To do this you can use microwaves- hence how we cook our food.
And we lower the temperature and it slows th emolecules down, then slowing the molecules down would decrease the temperature.
BUT then what would we need to use to sow the molecules down???
Macrowaves? (wavelength higher than 10^4)?
Some other aternate electromagnetic method?