Datacenters are always nice: nothing but servers, switches, cables and a lot of fan noise which is, surprisingly, quite soothing. The only downside is that I'm forced to stand in the "hot alley".
The way it works is this: A datacenter is basically just a huge hall with cages that hold the servers. Back in the old days they also had massive air conditioners to cool that entire hall. Then someone got smart and figured out that they didn't have to cool the entire hall, but just a small section by using cold- and hot alleys.
The way that cold- and hot alleys work is pretty simple: Servers keep them self cool by sucking in air from the front of the server, and blowing it through the inside to the rear. So if you make sure that the front of the server is in some kind of tunnel, then you only have to cool that tunnel. The servers will suck in the cool air, and blow it out the back. The front of the cage holding the servers, is in the tunnel, and the back is out in the open. This saves a lot of energy, due to the smaller air conditioners.
But, yeah... when you have to stand in the "hot alley" for a longer period, it's not so great. It's at least 35° Celsius, and the air humidity is very low. Quite the sauna indeed, except there's no steam and naked people here (I hope )