A thermal management system comprising: a battery (163, 272) through which a heat medium flows; a radiator (120, 231) through which the heat medium flows; a refrigeration cycle (150, 240) through which a refrigerant flows; a chiller (142, 220) configured to exchange heat between the heat medium and the refrigerant; and a switching valve (180, 280) configured to switch a first circuit mode and a second circuit mode, wherein the first circuit mode is a mode in which the chiller (142, 220) is thermally connected to the battery (163, 272), the second circuit mode is a mode in which the chiller (142, 220) is thermally disconnected from the battery (163, 272) and is thermally connected to the radiator (120, 231), characterized in that the thermal management system includes: a first temperature sensor (193, 292) configured to detect a chiller temperature that is a temperature of the refrigerant flowing through the chiller (142, 220); a second temperature sensor (192, 291) configured to detect a radiator temperature that is a temperature of the heat medium flowing through the radiator (120, 231); a temperature adjustment device (112, 151, 133, 151, 263) configured to adjust the temperature of one of the heat medium and the refrigerant; and a control device configured to control the temperature adjustment device based on the chiller temperature and the radiator temperature, and the control device is configured to, in a case where switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve (180, 280) during a heating operation of the refrigeration cycle (150, 240), control the temperature adjustment device to reduce a temperature difference between the chiller temperature and the radiator temperature prior to the switching. a battery (163, 272) through which a heat medium flows; a radiator (120, 231) through which the heat medium flows; a refrigeration cycle (150, 240) through which a refrigerant flows; a chiller (142, 220) configured to exchange heat between the heat medium and the refrigerant; and a switching valve (180, 280) configured to switch a first circuit mode and a second circuit mode, wherein the first circuit mode is a mode in which the chiller (142, 220) is thermally connected to the battery (163, 272), the second circuit mode is a mode in which the chiller (142, 220) is thermally disconnected from the battery (163, 272) and is thermally connected to the radiator (120, 231), characterized in that the thermal management system includes: a first temperature sensor (193, 292) configured to detect a chiller temperature that is a temperature of the refrigerant flowing through the chiller (142, 220); a second temperature sensor (192, 291) configured to detect a radiator temperature that is a temperature of the heat medium flowing through the radiator (120, 231); a temperature adjustment device (112, 151, 133, 151, 263) configured to adjust the temperature of one of the heat medium and the refrigerant; and a control device configured to control the temperature adjustment device based on the chiller temperature and the radiator temperature, and a first temperature sensor (193, 292) configured to detect a chiller temperature that is a temperature of the refrigerant flowing through the chiller (142, 220); a second temperature sensor (192, 291) configured to detect a radiator temperature that is a temperature of the heat medium flowing through the radiator (120, 231); a temperature adjustment device (112, 151, 133, 151, 263) configured to adjust the temperature of one of the heat medium and the refrigerant; and a control device configured to control the temperature adjustment device based on the chiller temperature and the radiator temperature, and the control device is configured to, in a case where switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve (180, 280) during a heating operation of the refrigeration cycle (150, 240), control the temperature adjustment device to reduce a temperature difference between the chiller temperature and the radiator temperature prior to the switching.