The invention relates to a device and a method for generating a positive pressure in a tank for liquefied gas on a refrigerated vehicle with an evaporator for the liquefied gas, in conjunction with which the evaporator is connected in a fluid-conducting fashion to the tank via a line for liquefied gas, and in conjunction with which a valve is arranged in the line, comprising the following method steps: opening the valve so that liquefied gas exits from the tank and into the line; closing the valve in such a way that a quantity of the liquefied gas remains in the line and is able to flow back into the tank; heating the quantity in the line. The invention also relates to a method for the supply of liquefied gas, and a device for generating a positive pressure in a tank for liquefied gas in a cooling system, in conjunction with which the method according to the invention for generating a pressure is utilized. The invention permits a particularly efficient and reliable cooling of products in a refrigerated vehicle.