How does heating cause motion? W.R.T. Newton's laws a force is required to change the state of rest of a body. Then how does heating cause a particular object's atoms and molecules to wiggle ? What is the force being applied when you heat something ? What is thermal interaction?
 A: heating is basically the increasing of average velocity of an object's atoms. they only "wiggle" because there are simply too many of them packed in a small volume that they dont go far before crashing into each other--hence the apparent random directions of motion (Brownian motion). these collisions are where the kinetic energy transfer happen and Newtonian physics apply accordingly. to answer the question, you heat something by placing it on another material whose atoms are vibrating faster and let the collisions do the work. at the microscopic scale this is known as kinetic theory. macroscopically, we just call it conduction.
even turning on an electric kettle, using electricity to produce heat, is due to collisions between charge carriers like electrons colliding with metal nuclei in the heating element. these charge carriers are moved by the electromotive force, aka voltage, which at the power station was more than likely produced from kinetic forces developed from the burning of fuels.
which brings us to radiation--the other method of heat transfer. in this regime the force being applied is due to the change in momentum of photon(s) when an atom/molecule absorbs it. the reason you feel warm under a spotlight 30ft away is because of radiation.
any interaction which causes the average velocity of an object's atoms to change can be called a thermal interaction.
