Not nitrogen-cooled, but liquid-cooled overclocked rackmount servers (with consumer gaming CPUs rather than the usual Xeon CPUs) are a thing in HFT.

They’re crazy because they are so unstable that you basically can’t reboot them and expect them to reliably come back up, so you are stuck on that given kernel version and firmware etc (important for eg the custom network cards that often want firmware updates).

You just turn it on, run it for like a year, and then it dies and you trash it and get a new one delivered.