This is most unfortunate but in proper district heating systems the scalding hot district circulation water never touches your house's heating / warm water. A heat exchanger is employed to insulate the different circulation systems. For example, my house has district heating and the warm water side is capped at +65C to protect against burns.

It's still pretty damn hot of course but I've never had any problems like you described, and I've lived in a dozen different houses in my city - all with district heating. Probably the system in the dormitory was somehow badly designed or incorrectly tuned.

I’m not positive I would have been scalded if I didn’t do that, but I do know that just turning on the cold line would yield at least uncomfortably hot water.

Why was the cold water line hot?

It was next to the hot water line and not insulated (enough) and it had pretty much just been sitting there all night.

Lucky you didn't get legionella. That is not up to spec, cold water lines should always be below 25°c. I have never seen such an installation, even in development countries it was done correctly.

> That is not up to spec, cold water lines should always be below 25

Yikes, that's tough. In my city, the cold water pipes are buried close enough to the surface and the brutal sun that it comes out of the tap about 27-29c during the day.

same, been in two developing countries with similar heating system, never seen such a problem. sounds disturbing

It's possible there's a faulty faucet mixing valve somewhere in the building causing hot water to mix into the cold line.

The hot water from the cold tap reliably went away once the water started running which is what made me think that it was sitting still next to the hot water that caused it