system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did the ancient civilizations used to make ice?
gpt
They didn't make ice. Wealthy people would have giant blocks of ice shipped to them from cold areas, keeping it cold by packing it in a lot of wood shavings as insulation. It would get shipped by boat or animal drawn cart. Before that was a feasible thing to have done, only people in cold areas had ice.