Power equipment controls the electricity that keeps society running, but it also produces lots of heat that must be dissipated. Actively cooling this heat only consumes more energy, feeding a vicious cycle. A promising, zero-energy solution is passive evaporative cooling using a sorption-based atmospheric water harvesting (SAWH) material. The sorbent captures water vapour overnight and releases it in the day. This daytime evaporation absorbs heat, cooling the surroundings. However, many SAWH materials get hot under the sun, challenging their ability to chill heat-generating devices outdoors. A new article in Advanced Materials addresses this issue by combining sorption-based evaporative cooling with passive daytime radiative cooling, another unpowered cooling method that reflects sunlight and emits it into space. By electrospinning a metal–organic framework composite into light-scattering microfibres, the team obtained a moisture-sorbing material with a sunlight reflectance of 0.98. Tested outdoors, the hybrid-mechanism material cooled the oil of a power transformer by about 25 °C more than natural cooling alone.