I live in Las Vegas and have had KNC Super Jupiter modules running all summer in my garage at temperatures well above 100f with absolutely no cooling other than a box fan to move the air. And I have recently added some S3s. Previously I was running BFL Singles and S1s in the garage but shut them down because of electricity cost.
I think the issue comes when we're looking at ASICs and GPU farms like traditional server rooms. Modern GPUs, for instance, can run 70-100*C all day every day, no problem, with exhaust in excess of 125*F. This isn't old, dusty equipment we plan on keeping operational for 20 years and which we absolutely need to not spontaneously combust at any time, but new, clean equipment able to hold its own in high-temperature environments we plan on being in an operational state for maybe 3-5 years. Is it better for the hardware to run it in a <75*F room with good airflow vs. a 110*F room with good airflow? Hell yeah, but fuck your hardware - money's more important. (and fire extinguishers! and keeping your hardware spaced apart!) People put themselves in ev- situations just because they want to be safe - because they're over-invested, I'd guess.
-So when people start coming up with dumbass ideas like putting their hardware in a closed mini-fridge, I start getting pissed off. 70*F highs in Summer vs 100*F highs in Summer doesn't make THAT big of a difference when your GPU can fucking boil water. You just want to get as much of that scalding-hot heat out. Maintaining clean airflow's way more cost/energy-efficient, quieter, and multitudes less retarded than trying to use air conditioning (with very, very few exceptions). Nature's air, in the majority of cases, is your best bet - just make sure it ain't skanky-ass dirty. I can't even imagine how filthy rich HVAC companies in Chinese and Indian cities are.