Worldbuilding

For these purposes "cold blooded" means having a low metabolism. Let's say we have a race of cold blooded sophonts. They have to regulate their body temperature externally by basking, and go a long time between feeding.

Between meals they only move to get in and out of the sun or artificial heat source. They're physically lethargic but mentally they're just as active as a human would be when awake. The result is a lot like when I have insomnia. Can't/don't want to move, but brain going a mile a minute.

They have grasping hands but can't use them well or at all when in this low energy state, but they can speak. Since most of their life is spent this way, they develop a strong oral culture, writing little but saying much. They spend these extended periods of torpor in groups, swapping stories and philosophizing.

Material culture is scarce, since any large structures must be built very slowly in stages during their active periods or in parallel with many many workers. They don't need to develop agriculture, since their caloric intake is much less compared to a human, and a hunter-gatherer lifestyle can support a much larger group.

I imagine them becoming a society of monks and philosophers, meditating and pondering the nature of things. They're not perfect pacifists but are less likely to engage in conflict because it wastes energy.