If you want a cheap simulation of hypoxia sit in a sauna over 180 degrees. The partial pressure is such that your blood spO2 drops to around 92% which is the edge of hypoxia.
The reason for this is Boyle’s gas law, temperature and pressure are related.
For years; even though I had been a firefighter and Dive Med, I thought of the Sauna’s “anxiety and lethargy” and other symptoms to be effects of heat.
I’ve seen heat fatigue, stress and strokes due to working hard in 800F ovens…
But it took years for me to stop and think a moment that the sauna’s symptoms are nothing like Heat-related injuries.
I thought about it, came up with the partial pressure O2 theory, took in a pulse ox one day, and BAM, sure enough ---- My spO2 was around 93 most of the time. I could change it based on the temperature. I pushed my sauna to 218F and that was enough for me.
So pretty much; scientifically speaking; Sauna is a good example of hypoxia.
PS - if I remember the math correctly; 180 degrees will work out to ~18,000 feet. Depending on how tolerant of actual heat and how well sealed the sauna is is how much a dose of 18,000 feet you’re going to get.
Oh and the vasodilation helps with perfusion so you’re going to be more tolerant of oxygen-injuries that way.
Which leads me to wonder if Flight Medicine has approved of blood thinners and NO2 etc for helping with hypoxia? But I digress, at 35,000 feet it won’t matter.