Any metal surface that is exposed to temperature variations will inevitably suffer from condensation but there are ways to mitigate against this. Empirical evidence shows that he corrugated construction of modern containers (compared with flat roofs of the early containers) helps prevent condensation and no doubt the paint used also helps. The roof of a new container is slightly bowed to give an upward arc so that external water does not lie on the roof. Where water lies on the roof of a container it lowers the temperature of the metal and causes condensation on the opposite side of the steel. Condensation is more likely to occur on used containers that have roof dents where water gathers. Condensation is more likely to occur when a container is sat on cold, damp ground such as exposed soil or a flooded area; the cold from the earth permeates the container above and reduces the temperature thus causing condensation. All air has moisture in it and it is this that condenses when the temperature drops so reducing the amount of moisture in the air inside a container will prevent condensation; this can be done by ensuring items are only placed in a container on a dry day if possible; a container can be vented on a dry day by opening the doors to allow damp air to circulate out of the container and be reduced by dryer air. Also, an item called Absorpole can be placed inside a container to absorb moisture from the air over a period of time.