The psychogenic fever seems to have effects that last for at least a month (you're not that quick to refeed) but it is only stressful (but extremely so) when you initiate the experience.
We've managed to initiate it in two people a small number of times but we're nowhere near a protocol that would be repeatable.
If you have a good imagination you can amplify your emotions and reach a "fever pitch" even if you don't have anything real to fight it.
This raises both of our body temperatures for about 48 hours, I lose about 5 kg over the next two weeks (the weight loss continues after the fever is not noticeable) and kept it off.
If I were trying to make it repeatable I'd assemble an encounter group and either have the group gang up on an individual or create a moral injury situation, maybe both at the same time. (e.g. the latter is the most repeatable way to produce harmful stress but the damage is also enduring, if somebody who was in the crowd felt guilty about participating or being complicit in the bullying that's the worst kind of stress you could give someone.)
https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0...
Tibetans claim to have a way to do it.
I have gotten uncomfortably hot when I visualized a phoenix and merged it with my avatar in the physical world but I tested it and it doesn't raise my core temperature.
It is very easy to use biofeedback to control your peripheral temperature (that's what a "mood ring" is good for) but core temperature is harder. I measure core temperature with a thermometer that goes under my tongue but maybe I could get one of those in-ear thermometers to be wearable in a meditation session.
Additionally, ganging up on an individual explicitly as a weight loss plan sounds like a great way to develop an eating disorder, given that simple exposure to the pressures of instagram is known to do this to girls.
What? O.o