Thank you very much for all the advice!!! We are currently in Egypt and we have only 800kms more to go to reach Cairo. Temperatures are still pretty high 43 Celsius (110 F) during the day. So after the first day riding under the heat in Sudan we have decided to wake up at 3am and try to finish riding before 9am.
Below is a pic of my gf while are taking a break from then sun and from the hot air. We stopped every hour or so to get out of the sun, get all our gear wet, drink water and cool a little bit off!