The simum has been described as a "poison wind", being dry and very hot, sometimes in excess of 55 ºC. "Soum" is Arabic for poison.
It is mentioned by James Joyce in A Portrait of the Artist as a Young Man:
Stephen's heart had withered up like a flower of the desert that feels the simoom coming from afar.
And in the film of The English Patient, Almasy describes the simum in violent terms:
...the Simoon, which a nation thought was so evil they declared war on it and marched out against it in full battle dress.