It is important that condensation does not occur as it encourages rot. Too rapid cooling will cause stress and damage. Good ventilation and circulation is important. Higher humidity promotes root growth and bulb decay. If onions are to be stored outside for a brief time prior to shipping, they must be in a shaded area.
Direct sunlight can warm the onions too much and result in translucent scales.
Translucent scales can cause serious losses, especially if shipment is delayed and the onions sit in storage. This chemical will prevent sprouting. The onion's temperature must be brought up to the packing room temperature very slowly over a two to three day period. Wet onions must be dried prior to shucking, a loss of time and income. If the onions are artificially heated to bring their temperature up to the packing room temperature, too much moisture can be removed.