A mobile air conditioner, comprising: a first heat exchanger having a first interface and a second interface for a refrigerant to enter and exit; a phase-change energy storage heat exchange device, including a second heat exchanger and a phase-change energy storage working medium, wherein the second heat exchanger and the phase-change energy storage working medium are capable of exchanging heat therebetween, and the second heat exchanger has a third interface and a fourth interface for the refrigerant to enter and exit; a first refrigerant pipeline, connected to the first interface and the third interface; a second refrigerant pipeline, connected to the second interface and the fourth interface; characterised in that the mobile air conditioner further comprises: a temperature detection unit, configured to detect a temperature of the phase-change energy storage working medium, and send out a first signal when detecting that the temperature of the phase-change energy storage working medium rises to a first preset limit; a reminding device; and a controller, electrically connected to the temperature detection unit, wherein the controller is configured to send out a first instruction in response to the first signal, and the first instruction is used for triggering the mobile air conditioner to stop operating in a refrigeration mode, or the controller is configured to send out a second instruction in response to the first signal, and the second instruction is used for triggering the reminding device to execute a reminding function. a first heat exchanger having a first interface and a second interface for a refrigerant to enter and exit; a phase-change energy storage heat exchange device, including a second heat exchanger and a phase-change energy storage working medium, wherein the second heat exchanger and the phase-change energy storage working medium are capable of exchanging heat therebetween, and the second heat exchanger has a third interface and a fourth interface for the refrigerant to enter and exit; a first refrigerant pipeline, connected to the first interface and the third interface; a second refrigerant pipeline, connected to the second interface and the fourth interface; characterised in that the mobile air conditioner further comprises: a temperature detection unit, configured to detect a temperature of the phase-change energy storage working medium, and send out a first signal when detecting that the temperature of the phase-change energy storage working medium rises to a first preset limit; a reminding device; and a controller, electrically connected to the temperature detection unit, wherein the controller is configured to send out a first instruction in response to the first signal, and the first instruction is used for triggering the mobile air conditioner to stop operating in a refrigeration mode, or the controller is configured to send out a second instruction in response to the first signal, and the second instruction is used for triggering the reminding device to execute a reminding function. a temperature detection unit, configured to detect a temperature of the phase-change energy storage working medium, and send out a first signal when detecting that the temperature of the phase-change energy storage working medium rises to a first preset limit; a reminding device; and a controller, electrically connected to the temperature detection unit, wherein the controller is configured to send out a first instruction in response to the first signal, and the first instruction is used for triggering the mobile air conditioner to stop operating in a refrigeration mode, or the controller is configured to send out a second instruction in response to the first signal, and the second instruction is used for triggering the reminding device to execute a reminding function.