1. Upgrade the refrigeration equipment of the stall car and choose more efficient refrigeration equipment, including freezer or refrigerator, to ensure that the refrigeration equipment can provide enough refrigeration power and maintain a stable low temperature.

2. Heat insulation treatment shall be carried out inside the booth, and heat insulation materials shall be used to reduce heat conduction and penetration. Thermal insulation materials can be installed on the wallboard, ceiling and floor inside the car body to reduce the influence of external heat on the refrigerated space.