methinks different culture, but same concept? first nation do not use tents they are wooden structures, but sounds great the world you have read.
some outsiders are allowed but not on the lands, they are different public ceremonies depending on time, location, etc. it would have to be something mentioned publicly.
some people do feel connected to something ... observers and non natives might say Source. Pure energy.
Now I am sure Robert Jordan was inspired by First Nation philosophy. He also talked about the Source, a source for infinite amount of energy which could be reached out to and wielded.
I guess I should correct that and say outsiders would say that First Nation call it something different. There are non natives that build sweats and who knows, maybe research your guy and see his background of experience. I personally feel as I’ve seen non natives attend that they can be healed but it’s viewed differently.
No I mean he may have been part of such a ceremony or may be read about it somewhere and then added his writer's imagination on top of it to create his fantasy world. This, however, may or may not be true but the similarities are there
hahah may or may not ahahahah
well many cultures have something similar so maybe ...