Radiative cooling face mask based on mixed micro- and nanofibrous fabric

•A novel face mask with superior radiative cooling performance is prepared.•PLA and silk are chosen for their high emissivity in the mid-infrared region.•Tailored fiber size distribution provides efficient reflectivity of sunlight.•Mixed micro- and nanofibrous structure presents excellent filtration performance.•Air flow and particle motion passing through the fiber assembly are simulated.