Satellites have heat pipes and with careful design, they can passively move heat from the hot parts to the cold parts. It uses technology not dissimilar to your refrigerator. Zero gravity is a critical element.

en.m.wikipedia.org/wiki/Heat_pipe

A year and a half ago, I went Kayaking on the Cuyahoga River. The kayak company was called Burning River Adventures. 😁 I had a great time. Beautiful river.