An absorption plate for a vehicle is crossed by a stream of liquid absorbent fluid flowing between two exchange surfaces arranged relatively opposite one another. The exothermal absorption of a coolant fluid in vapor phase takes place through the exchange surfaces by increasing a concentration of the coolant fluid in the absorbent fluid. The relative arrangement of the two exchange surfaces forces at least one portion of the stream of absorbent fluid to pass at least once through one of the exchange surfaces and causes mixing of the stream of the absorbed fluid.