I'm happy to grant that if you change my example to an entirely different one where someone is in a climate controlled environment, such that the temperatures I mentioned are not being experienced, it is true that people will survive in this different example, but to me that seems to miss the point.
I think our operative notions of objective reality in this context do not hinge on claims to absolute knowledge, but are about distinctions between things we already agree to be objective in the sense that people are already comfortable granting, e.g. how tides work, what safe ranges of blood pressure are, how physics and math work, what really happened on this day in history etc. Those are one kind of thing, and then on the other side you have questions of opinion or societal consensus.
So the canonical example would be, are opinions about the "fairness" of a tax policy more like a math problem with a right answer, or more like opinions about the "best" type of cheeseburger. The answer isn't that there's no such thing as the former category and therefore it's in the latter category by default.
The motivation, of course, is to say that some things fall into one category and some things fall into the other. I think for purposes of this conversation the philosophical move of taking this kind of Cartesian skeptic approach to ALL of objective reality, would throw out ALL of science, even the stuff that people would normally agree is real, when what it was supposed to do was draw a line down the middle to help us understand which things are the sciency things and which things are the opinions/values/societally negotiated things. Extreme skepticism in this context, instead of helping refine that distinction, bombs the village in order to save it. I even go so far as to argue that such an extreme skeptic view would make it impossible to establish that anything was even really socially negotiated in the first place, but maybe that's a can of worms for another time.
It's true that a kind of contextual embeddedness is characteristic of human experience. But I think it's deeply confused to think that such a thing is a counterpoint to objectivity, because the bones of context are made of objective things. The climate-controlled space capsule insulates humans against the coldness of space due to facts of the matter about the nature of temperature, the materials science that makes insulation possible, and biological facts of the matter about being a human being. Science is perfectly alert to this kind of contextual variability. Those values would be what they were even if social negotiation concluded otherwise.
What I really think is as follows: saying something isn't like science, means, in practical terms, that it's unrealistic to try and model it and come out with clear prescriptions. I think treating it like the upshot is supposed to be a wholesale denial of objective reality would count as a misdiagnosis. Sometimes the skies clear and we do know, for real, that (say) climate change is real, or that enforced sleep deprivation really is torture. Wholesale denial of objective reality leaves you with no theory as to why the skies can possibly clear in that way, or why people can be right about polarized topics.
Anywho I wouldn't make a response this long if you were not giving a very thoughtful gloss on the topic so kudos for imo one of the more nuanced takes in the whole thread.