Abstract: A method and apparatus for controlling the environment of cargo through lateral ventilation. The method provides for a controlled fluid to be supplied into a cargo compartment having a lateral portion, the fluid being supplied through a vent in a supply-conduit adjacent the lateral portion. In practice, this result can be achieved by building a structure that encloses a cargo compartment having a lateral portion, running a supply-conduit adjacent the lateral portion, connecting the supply-conduit to receive a controlled fluid from outside the cargo compartment, and conducting the fluid into the cargo compartment through a vent in the supply-conduit. On mixing with the environment within the cargo compartment, the fluid will influence components of the environment, for example the humidity and the temperature.