Several hundred thousand people from the US have recent experience working in 120-140F weather wearing 50-100 pounds of equipment and heavy clothing, often doing labor a bit more strenuous than pulling drives or racking servers.
If I read your comment correctly, it sounds like you're comparing healthy young people who have undergone extensive physical training and testing to technicians of a highly variable age who have gone through no such selection and training? Or are you really suggesting that any old technician can run around in a desert carrying military equipment with zero training or physical aptitude, or vice versa?
The heat in Iraq goes up to 120F, and some soldiers have been hospitalized, or even killed by the heat. In the extreme case of 140F heat, I'd imagine soldiers would only be allowed out in if there's a very good reason. >120F heat should be treated like a sandstorm - an environmental hazard which you try to avoid.
Well regardless, firefighters have plenty of experience with running into hot as balls buildings and doing physically exerting things. If he wasn't referring to firefighters, then he should have been.
I was definitely thinking of Iraq because I'd say national guard are a pretty broad cross section of regular Americans, but firefighters, steel mill or industrial workers, etc are all highly relevant too.
Relatively extreme temps are an issue, but can be overcome. If it requires a couple weeks of practice for your staff to get used to working in 100-120f low rh environments but saves huge amounts of energy, it is worth considering.
In a cloud hosting environment, you could eventually have non safe temperatures in active operation, lots of redundancy, and just do all your human maintenance during reduced power/temp windows all at once. Sort of like treating the data center as the inside of a computer. Either run multiple facilities or partition by thermal suite or hae the equipment power management be able to throttle cores for reducing heat.
Disneyworld in Orlando Florida with an average summer temperature of 91F responds to dozens of heat stroke cases with people wearing shorts and shirts, merely walking around and waiting in lines to enjoy rides.
Yeah, there's a wide variation in training, condition, and the level of care/equipment/hydration, and the results (and there are lots of heat injuries in the military, too). The OSHA limits are clearly not the limits of human performance (either low or high). One of the things is you acclimate to it over a period of a week or two fairly successfully, so if there were a datacenter which constantly operated in that range, you should be able to get staff who can handle it. (I'm sure steel mills and other industrial facilities have high temperatures, too).
