Thermoregulatory clothing plays an indispensable role in maintaining body thermal comfort and achieving building energy savings in response to fluctuating ambient. Existing temperature-adaptive clothing without external energy input has very limited thermoregulatory power because of the lack of simultaneous regulation of multiple heat-dissipation pathways. Here, we report thermoregulatory clothing with temperature-adaptive multimodal body-heat regulation (viz. convection, radiation, and sweat evaporation), which can automatically adapt to temperature change (15°C–35°C) within seconds by incorporating mechanically and infrared optically tailored metalized polyethylene actuators into textiles. Based on thermal manikin tests and thermo-physiological modeling, it demonstrates that the designed clothing can expand comfort zone by more than 2°C on both cold and hot sides, corresponding to about 30% building energy savings when used in indoor environment. The smart clothing can also significantly improve the comfort and performance of wearers when exposed to fluctuating or extreme environmental conditions.