When you travel to any international country, particularly less-developed countries like Egypt, it is paramount to have your personal documentation in order. Pack copies of your visa, passport, identification and any other document that will help Egyptian authorities to identify and assist you should you find yourself in a precarious situation. Keep the originals in a safe place, such as a secret compartment of your luggage or purse, and copies on your person and with your traveling companions.
Because the sun is brutal in most parts of Africa, it is important to bring along proper protection. In addition to sunscreen with as high an SPF factor as you can find, you should also pack a large hat and sunglasses. Purchase the sunscreen in particular before you travel because you may not be able to get the same quality in Egypt as you do in the United States. If you must purchase sunscreen in Egypt, spend the extra money to buy a brand you are familiar with so that you can be confident in the level of protection.
Biting flies are fairly rampant in the desert, so bring along insect repellent with plenty of DEET. Also, bottled water is an important part of the packing list, as jaunts through the desert can easily leave you dehydrated and drained. Moreover, while water is plentiful in Egypt, it is best to drink bottled water to lessen your risk of exposure to parasites.
Egypt's fluctuating temperatures can be deceptive. Because of its desert climate, temps range from extremely hot during the day to fairly chilly at night. To combat the fluctuation, dress in layers so that you can add or remove clothing as necessary. Also, cottons are best, particularly those with wicking properties, to keep you as cool as possible on your excursions.