what can I do to stop the Hurghada sun damaging my clothes?

I have a unusual problem and wondered if any textile experts can advise me. To be honest to save on air costs I keep my luggage to a minimum, and leave my summer clothes in a dark area in cases in my flat in Egypt but to my dismay on my last visit to Egypt when I opened my cases most of my brand new white items were badly soiled with orange stains. My husband said because of the heat it had degraded the fabrics. Has anyone had this problem. I keep the blinds in the window closed minimising the sun but yes heat cannot be prevented . What can I do or how can I protect the clothing.