In my story there are complex organisms that are essentially sacks of water with organs and are the size of a basketball. They have so advanced technology that they built a city in a large crevice. They hop around to move.
The crevice is around 300 meters tall, 3 kilometers deep and is made entirely of rock. Outside the crevice, it’s around 60 degrees celsius. My question is, is it possible that these organisms can survive in this crevice without freezing or overheating? (Assume that they will die if the water inside them freezes or goes above 80 degrees celsius.) If it’s too cold, is it possible that they install heating systems to heat it up to a point where it’s livable?