Of course they're properly cooled, and I'd bet they're running cooler than most peoples open air rigs, because they are in a data center that has AC, and are in a chassis that has been engineered with cooling that can handle the airflow required by FE cards. No one's going to risk the cost of 10 x 1080 ti cards without proper cooling!
This is the way things are done in the enterprise deep learning arena, and companies like Supermicro sell setups for 10 x Tesla cards, or consumer 1080 ti's work just fine:)
That picture is from a system with this chassis -
https://www.supermicro.com/products/system/4u/4028/sys-4028gr-tr.cfmNo way... those gpus must be throttling hitting 80 or more °C when moderatly loaded with some minning or other processing stuff. I've just played too much with gpu's, cases, vents etc. to accept those statements.