Note that this is not as difficult as it sounds. Here is a video explaining how laser cooling works, by using 6 lasers pointing towards a sample with a wavelength just longer than the absorption wavelength of its atoms in order to decrease its momentum regardless of which way it's moving (details near the 2:20 mark):

https://www.youtube.com/watch?v=hFkiMWrA2Bc

So mainstream cryogenics could be a side benefit of technologies like this.

After rereading this, I'm not sure if the ESR itself can perform cooling.