system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are the ceilings in supermarkets so high?
gpt
1) To keep it from being claustrophobic. If it had short ceilings being in isles would feel like tunnels. 

2) Heat management. There are dozens if not hundreds of people in the store at any given point in time. That produces a lot of body heat. It is cheaper for them to have high ceilings for that warm air to go to and be replaced by cooled air from the AC ducts that are set lower.