system
Given the following post, respond as if you're commenting on Reddit:
human
[General] How do spaceships deal with heat?

No system is 100% efficient and some waste heat is generated, even on a spaceship. So how do ships across the multiverse handle this, how do they dump their excess heat? 

The UNSC uses a multistage cooling system for their fusion reactors, where by hot coolant can be dumped and new cold coolant added to the system. Ships in Citadel Space use systems that convert heat to light and direct that away from the hull, other ships use heat sinks to store the heat to be purged later.
gpt
The weird twisty shapes that a lot of ships have are actually designed to give them a high surface area, which makes radiative cooling easier. It's why advanced civilisations don't really build their ships around a rocket-shaped design: unless the ship is very small or only meant for short trips outside the atmosphere, it's just not an efficient way of cooling them.

It also helps to put the engines and generators on struts away from the living space, so that habitable areas don't heat up too fast.