While in Egypt, I would NOT recommend wearing shorts or any sleeveless tops unless you are at the beach. I would recommend loose-fitting clothing,(pants or skirts) and shirts that have a little bit of a sleeve (nothing sleeveless). You will get a lot of attention as it is, there's no need to attract more attention. When I was there I found some of the Egyptian men to be a little bit "grabby." It is just culturally more appropriate. Also, it protects you from the sun. As in many places of worship, you will be expected to have your arms and legs covered.