Humidity Levels and UV protection for figures, etc.?

[pho3nixinflight]

My storage unit is in a climate controlled warehouse but the unit itself has a mesh ceiling and the warehouse is light by florescent lights, which are hanging maybe 30 feet in the air. I always knew sunlight was bad but ignorantly never though of the florescent lights being much of a problem. The quickest and easiest solution I can think of is to get some cardboard boxes from somewhere like home depot and box everything up, but I'm wondering if that's actually a good idea or what would the potential drawbacks be, or things I should consider with doing that?
Also, I noticed the humidity level in the warehouse was at 58 and the temp was at 71F. I'm curious if this is acceptable or not? I live in the southeast (USA) so it gets very hot and humid here.
I'm rather new to collecting so any insight on these issues would be greatly appreciated.