system
A chat on subreddit /r/pcmasterrace
human
Any crypto miner, GPU or CPU can be used as a heater.

Since I have a few extra x99 boards and xeons I'm gonna use for machine learning rigs, I have them mining RandomXmonero on Nicehash right now, as well as using my 4090.
gpt
use stable diffusion and write a script to constantly generate high quality anime tiddies while also keeping your house warm!