Yes. You must be able to control the temperature of a building densely packed full of hot radiators. You might be able to avoid active AC within the Arctic circle but you'd m still want to filter that incoming (very) cold air, at which point maybe you might as well basically have an AC system. And yes, you must ensure you can survive a failure because these systems do fail (normally when you need them most) and then otherwise everything inside cooks.

The arctic is warming much faster than other places. See eg this recent article about record 38C temps in siberia: https://www.sciencenews.org/article/siberia-verkhoyansk-reco...

Datacenters always have A/C I thought?

Thanks :)

Google and other companies do make risk assessments including temperature scenarios.