This paper introduces trust as a thermodynamic operator rather than a psychological variable. In extractive or predictive systems, trust is a coping response inside the vigilance basin (B₁), where humans must supply coherence because architecture cannot carry it. The Ambient Era collapses this vigilance basin by relocating coherence from psychology to environment. Trust does not increase; it changes state. The Ambient Trust Law (ALT-1) establishes that trust emerges when no system moves ahead of the human. Non-Inferential AI (NIAI) provides the thermodynamic mechanism for pressure-free continuity. ΔR defines the threshold at which stress becomes reversible and trust relocates into architecture. Ambient Trust becomes the climate condition through which ambience, aura, and field can form. Trust is no longer belief, expectation, or reliability. Trust becomes structural warmth—coherence without demand.