Plasmonic nanoantennas focus gentle beneath the diffraction restrict, creating sturdy subject enhancements, usually inside a nanoscale junction. Inserting a nanostructure throughout the junction can tremendously improve the nanostructure’s innate optical absorption, leading to intense photothermal heating that would in the end compromise each the nanostructure and the nanoantenna. Right here, we exhibit a three-dimensional “antenna-reactor” geometry that leads to giant nanoscale thermal gradients, inducing giant native temperature will increase within the confined nanostructure reactor whereas minimizing the temperature enhance of the encompassing antenna. The nanostructure is supported on an insulating substrate throughout the antenna hole, whereas the antenna maintains direct contact with an underlying thermal conductor. Elevated native temperatures are quantified, and excessive native temperature gradients that thermally reshape solely the interior reactor aspect inside every antenna-reactor construction are noticed. We additionally present that prime native temperature will increase of nominally 200 °C are achievable inside antenna-reactors patterned into giant prolonged arrays. This easy technique can facilitate standoff optical era of high-temperature hotspots, which can be helpful in functions corresponding to small-volume, high-throughput chemical processes, the place response efficiencies rely exponentially on native temperature.