Buildings can be effectively cooled by a bioinspired sweating-like action based on thermoresponsive hydrogels (PNIPAM), which press out their stored water when exceeding the lower critical solution temperature. The surface temperature is reduced by 15 °C compared to that of a conventional hydrogel (pHEMA) and by 25 °C compared to the bare ground. DOI: http://dx.doi.org/10.1002/adma.201202574