Electronic device comprising: - at least one heat source generating heat; - at least one cold point able to absorb heat; - a thermally insulating material the thermal conductivity of which at the temperature T f of use of the device is below a threshold S 1, this material thermally insulating the heat source from the cold point; and - at least one thermal bridge extending between at least a first end and a second end, these ends being thermally connected to the heat source and cold point, respectively; characterized in that: - the two ends of the thermal bridge are connected to the cold point and the heat source, respectively, by end pads; and - the thermal bridge comprises, between its two end pads, at least one thermal switch (56, 57; 97, 98; 130, 131) able to switch reversibly between: - a conductive state in which its thermal conductivity at the temperature T f of use takes a value λ c above the threshold S 1 in order to connect thermally the two end pads of the thermal bridge; and - a resistive state in which its thermal conductivity at the temperature T f of use takes a value λ r lower than the value λ c in order to insulate thermally the two end pads of the thermal bridge, the thermal switch (56, 57; 97, 98; 130, 131) comprising for this purpose a material (60; 100, 102; 138) of variable thermal conductivity able to switch, in response to a supply of energy, between: - a conductive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ c in order to connect thermally the two end pads of the thermal bridge when the thermal switch is in the conductive state; and - a resistive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ r in order to insulate thermally the two end pads of the thermal bridge when the thermal switch is in the resistive state; and - the electronic device comprises a control module able to switch the thermal switch between its conductive and resistive states. - at least one heat source generating heat; - at least one cold point able to absorb heat; - a thermally insulating material the thermal conductivity of which at the temperature T f of use of the device is below a threshold S 1, this material thermally insulating the heat source from the cold point; and - at least one thermal bridge extending between at least a first end and a second end, these ends being thermally connected to the heat source and cold point, respectively; - the two ends of the thermal bridge are connected to the cold point and the heat source, respectively, by end pads; and - the thermal bridge comprises, between its two end pads, at least one thermal switch (56, 57; 97, 98; 130, 131) able to switch reversibly between: - a conductive state in which its thermal conductivity at the temperature T f of use takes a value λ c above the threshold S 1 in order to connect thermally the two end pads of the thermal bridge; and - a resistive state in which its thermal conductivity at the temperature T f of use takes a value λ r lower than the value λ c in order to insulate thermally the two end pads of the thermal bridge, the thermal switch (56, 57; 97, 98; 130, 131) comprising for this purpose a material (60; 100, 102; 138) of variable thermal conductivity able to switch, in response to a supply of energy, between: - a conductive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ c in order to connect thermally the two end pads of the thermal bridge when the thermal switch is in the conductive state; and - a resistive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ r in order to insulate thermally the two end pads of the thermal bridge when the thermal switch is in the resistive state; and - a conductive state in which its thermal conductivity at the temperature T f of use takes a value λ c above the threshold S 1 in order to connect thermally the two end pads of the thermal bridge; and - a resistive state in which its thermal conductivity at the temperature T f of use takes a value λ r lower than the value λ c in order to insulate thermally the two end pads of the thermal bridge, the thermal switch (56, 57; 97, 98; 130, 131) comprising for this purpose a material (60; 100, 102; 138) of variable thermal conductivity able to switch, in response to a supply of energy, between: - a conductive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ c in order to connect thermally the two end pads of the thermal bridge when the thermal switch is in the conductive state; and - a resistive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ r in order to insulate thermally the two end pads of the thermal bridge when the thermal switch is in the resistive state; and - a conductive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ c in order to connect thermally the two end pads of the thermal bridge when the thermal switch is in the conductive state; and - a resistive phase in which the thermal conductivity of the material at the temperature T f of use takes the value λ r in order to insulate thermally the two end pads of the thermal bridge when the thermal switch is in the resistive state; and - the electronic device comprises a control module able to switch the thermal switch between its conductive and resistive states.