Probably should do it yourself, but answering these questions might help you:
-reason for being there - are you searching for something? trying to hitch a ride? got kidnapped and woke up to find yourself here?
-how long you've already stayed - i.e. are you physically drained? emotionally? why?
-what you have been doing and what you are doing / trying to do now e.g. are you walking, driving, trying to find water
-is this any normal dessert, or is there anything you are cautious of e.g. dangerous mammals
-who you are with and how that affects your surroundings
-what you are wearing, or what clothing you don't have that you need e.g. no shoes?
-where you are staying
-is it sunrise? sun down? midday?
-what is around you? - something? nothing? mysterious little houses in the distant?
-any disabilities? are you blind? deaf? paralysed in one arm?
-what is on your mind ? - a break up? your mother?
-how does the sand feel? or is there no sand? what kind of dessert (real or fictional) is this?
-etc
What will make your own description of the desert unique is the input of experiences (personal or fictional) and this character's reaction to his/her environment. That way, the product of your envisions will become much more vivid, rather than just 'it's really hot right now'.
Might also be a good idea to look at images of different desserts.
Good luck