I think there's been some recent research saying that DEET isn't actually that effective as a repellant any more. The mozzies seem to have got used to it and after a while it has no effect.
Some years ago, I worked for a company that made insecticides. When I was about to go on holiday the technical director told me to soak my clothes in permethrin. Apparently that is what the British army were doing at the time. Didn't really need to as having worked there for a while nothing seemed to bite anyway
Not sure whether its still recommended, or even if you can buy permethrin easily. These days it is rarely available as a pesticide in garden centres because other stuff is more effective and lasts longer. You can get it as headline shampoo though.
Lavender, rosemary, tea tree etc are all supposed by good repellents.
Not sure whether you need it for UAE.