- An installation for at least keeping meals placed on meal trays cold, including; • at least two isothermal carts for transporting meal trays each comprising: - an insulating enclosure defining at least one chamber accessible via at least one door and having at least one cold compartment, this chamber being provided inwardly with superimposed support means for keeping the meal trays in position; • a fixed terminal including a refrigeration unit and a cold control and regulating unit, characterized in that: • each cart is equipped on one of its faces with: - at least one air inlet mouth and at least one air outlet mouth communicating by sheaths, with the cold compartment, and - temporary coupling means with the fixed terminal; • the fixed terminal has two parallel walls each equipped with: - at least one cold air blowing mouth complementary to the air inlet mouth of a cart, to cooperate with them during the coupling of a cart with the fixed terminal, the blowing mouths communicating by channels with the refrigeration unit; - at least one air suction mouth, complementary to the air outlet mouth of a cart to cooperate with one another during the coupling of a cart with the fixed terminal, the air suction mouth communicating by channels with the refrigeration unit; - temporary coupling means, complementary with the temporary coupling means of a cart, to keep a cart in a fixed coupling position for which the blowing and suction mouths are tightly connected with the inlet and outlet mouths, respectively; • the control and regulating unit controls and regulates one and/or the other of the carts coupled to the fixed terminal. • at least two isothermal carts for transporting meal trays each comprising: - an insulating enclosure defining at least one chamber accessible via at least one door and having at least one cold compartment, this chamber being provided inwardly with superimposed support means for keeping the meal trays in position; - an insulating enclosure defining at least one chamber accessible via at least one door and having at least one cold compartment, this chamber being provided inwardly with superimposed support means for keeping the meal trays in position; • a fixed terminal including a refrigeration unit and a cold control and regulating unit, characterized in that: • each cart is equipped on one of its faces with: - at least one air inlet mouth and at least one air outlet mouth communicating by sheaths, with the cold compartment, and - temporary coupling means with the fixed terminal; - at least one air inlet mouth and at least one air outlet mouth communicating by sheaths, with the cold compartment, and - temporary coupling means with the fixed terminal; • the fixed terminal has two parallel walls each equipped with: - at least one cold air blowing mouth complementary to the air inlet mouth of a cart, to cooperate with them during the coupling of a cart with the fixed terminal, the blowing mouths communicating by channels with the refrigeration unit; - at least one air suction mouth, complementary to the air outlet mouth of a cart to cooperate with one another during the coupling of a cart with the fixed terminal, the air suction mouth communicating by channels with the refrigeration unit; - temporary coupling means, complementary with the temporary coupling means of a cart, to keep a cart in a fixed coupling position for which the blowing and suction mouths are tightly connected with the inlet and outlet mouths, respectively; - at least one cold air blowing mouth complementary to the air inlet mouth of a cart, to cooperate with them during the coupling of a cart with the fixed terminal, the blowing mouths communicating by channels with the refrigeration unit; - at least one air suction mouth, complementary to the air outlet mouth of a cart to cooperate with one another during the coupling of a cart with the fixed terminal, the air suction mouth communicating by channels with the refrigeration unit; - temporary coupling means, complementary with the temporary coupling means of a cart, to keep a cart in a fixed coupling position for which the blowing and suction mouths are tightly connected with the inlet and outlet mouths, respectively; • the control and regulating unit controls and regulates one and/or the other of the carts coupled to the fixed terminal.