This reminds me of a medical test I took at a hospital to diagnose dysautonomia. One of the features of the condition is reduced or absent sweating, so they got me to run on a treadmill-
No, just kidding. They put me in a room with heaters lining the ceiling. I was slathered in castor oil and iodine solution from neck to toes, then instructed to lie on a flat table and not move at all while they heated the room to somewhere between 45°-50°C (113°-122°F) for 50-odd minutes. The heaters were the only source of light after the test began so the room was bathed in a dim red light.
I've had some really awful illnesses and invasive medical tests before, but I look back on that experience and can only describe it as harrowing.
I don't know if it was just me and my connective tissue disorder, but for some reason the increasing pain of lying immobile for nearly an hour was significant by itself.
As I began to sweat successfully (yay?) I got to enjoy the creeping sensation of hundreds of water droplets tickling down my skin in 50% humidity and torturous heat, unable to flinch them away.
I spent the last 10 minutes tensed from head to foot with my eyes clenched shut and my teeth gritted, mentally rocking back and forth like a baby repeating 'Make it stop, please make it stop, I can't do this anymore, please, please, please...'
0/10, sounds like a joke when I tell someone in real life, only no one laughs. The hospital never sent the test results to my doctor in the end, so I can only assume that I don't have dysautonomia 🙃