Experimental setup and radiative cooling performance of PSHF_HP. (A) Setup for testing the radiative cooling temperature under clear sky. Inset: schematic of the radiative cooling measurement. (B) Temperature tracking of the air, PDMS film, PDMS/TiO₂ white coating film and PSHF_HP with various thicknesses at noon. (C) Continuous measurement of the radiative cooling power of PSHF_HP. Inset: schematic drawing of the thermal box apparatus with a feedback-controlled heater. (D)–(F) Solar irradiance, relative humidity and temperatures of the air, PSHF_HP and PDMS film on May 03–04, 2020, in Xuzhou city. (G)–(I) Solar irradiance, relative humidity, and temperatures of the air, PSHF_HP and PDMS film on April 27–28, 2020, in Xiamen city.