When this passively ventilated container is used to transport a cold cargo in winter from temperate latitudes into the tropics, this ventilation is ineffective, since the air flow would have to be reversed, with the hot external air having to flow downwards through the container as the cargo cooled (risk of sweat). This happens only to a limited degree, so meaning that the air exchange has to be caused by air circulation outside the container. This occurs more intensively on deck, due to the relatively high level of air circulation around the container, than in the hold, where the only air flow available is that generated by the ventilation system.