The servers for both cloud and virtualization, the storage servers and virtual hosts, are located in server farms that are in data centers. If these servers get too hot, the devices will fail. Therefore, in a data center, we have hot and cold aisles:
The cold aisle is where the cold air comes in and that faces the front of the servers. The rear of the servers face each other, they push out hot air into the hot aisles, and this is allowed to escape through a chimney. This way, the temperature can be regulated and this ensures the availability of the IT systems.