We report on nanothin multilayer hydrogels of cross-linked poly(N-vinylcaprolactam) (PVCL) that exhibit distinctive and reversible thermoresponsive behavior. The single-component PVCL hydrogels were produced by selective cross-linking of PVCL in layer-by-layer films of PVCL-NH 2 copolymers assembled with poly(methacrylic acid) (PMAA) via hydrogen bonding. The degree of the PVCL hydrogel film shrinkage, defined as the ratio of wet thicknesses at 25 to 50 °C, was demonstrated to be 1.9 ± 0.1 and 1.3 ± 0.1 for the films made from PVCL-NH 2-7 and PVCL-NH 2-14 copolymers, respectively. No temperature-responsive behavior was observed for noncross-linked two-component films because of the presence of PMAA. We also demonstrated that temperature-sensitive PVCL capsules of cubical and spherical shapes could be fabricated as hollow hydrogel replicas of inorganic templates. The cubical (PVCL) 7 capsules retained their cubical shape when temperature was elevated from 25 to 50 °C exhibiting 21 ± 1% decrease in the capsule size. Spherical hydrogel capsules demonstrated similar shrinkage of 23 ± 1%. The temperature-triggered capsule size changes were completely reversible. Our work opens new prospects for developing biocompatible and nanothin hydrogel-based coatings and containers for temperate-regulating drug delivery, cellular uptake, sensing, and transport behavior in microfluidic devices. © 2012 American Chemical Society.