Elasticity-gated thermal plasticity via superheating-mediated nucleation and growth in polymer networks

+ ΔT, where ΔT is set by thermal history and salt identity. Structural characterization reveals a hierarchical architecture of tight physical crosslinks and loose co-evolving domains, offering a universal design rule for history-responsive materials. We demonstrate reprogrammable freeze-exposure indicators for vaccine cold-chain monitoring to quantify sub-zero breach severity and duration. This work establishes intelligent matter capable of autonomous sensing, memory, and adaptive actuation.