When you start looking into storage options, you will soon find that you have two main choices: non-climate-controlled or climate-controlled storage. In most cases, unless you're storing only outdoor equipment, you will want to rent a climate-controlled unit. That is because climate control helps prevent a wide range of issues, including the following.
Where there is heat and moisture, there are often insects. You might figure insects are not a major issue if you are not storing food for them to eat, but some species of cockroaches, and even ants, are happy to eat items made from paper, glue, and even wood in some cases.