A heat absorption and radiation system uses a heat medium containing a rubidium-manganese-iron cyano complex, and is configured to release heat from the heat medium by applying a pressure to the heat medium and causing phase transition of the rubidium-manganese-iron cyano complex from a high-temperature phase to a low-temperature phase, absorb heat into the heat medium by releasing the pressure applied to the heat medium and causing phase transition of the rubidium-manganese-iron cyano complex from the low-temperature phase to the high-temperature phase, and repeat application of the pressure to and release of the pressure from the heat medium. Thus, it is possible to efficiently absorb and release heat through effective utilization of the characteristics of the rubidium-manganese-iron cyano complex.