Mitochondrial activation, parasympathetic shift.
Far-infrared photons (850–1,400nm) penetrate ~4cm into soft tissue and stimulate cytochrome c oxidase activity in mitochondria, supporting ATP production. The chamber's humidity and temperature drop sympathetic tone within minutes. Net effect: a body warmed and oxygenated, in a parasympathetic-dominant state — primed for the rest of the circuit.
