So what is body load? Cause I'd say there is a difference between feeling unusual sensations, energy type things flowing in your body as called a body high, or load when there is discomfort / sense of encumbering etc, and on the other hand getting physical side-effects which - as Xorkoth pointed out - are not vague / energy like (which is probably a result of an altered state of the nervous and endocrine system and terribly complex - just tbh more practical to approach with holistic terms). Instead it's virtually tangible, as tense hardening of bodily organs. (Perhaps not veins then, but what?) The idea that this whole sensation, including the 'interactive' palpability, is a type of hallucination actually does not seem favorable on Occam's razor.