1)
What is "Charishis"?
1.
Rashi citing Gitin 31b: When the east wind blows, it is Macharish (silences) all the other winds (negates their cooling effects); it is very hot. Targum Yonasan is like this (it silences).
2.
Radak: It is strong. It makes people like Chereshim (deaf) when it blows [Malbim - due to its great noise].
2)
What do we learn from "va'Yis'alef"?
1.
Rashi: He fainted. Radak - he could not bear the great heat, and his Ru'ach almost departed. This is like "Tis'alafnah" (Amos 8:13). Chazal said (one may not take a steam-bath before praying Minchah), lest va'Yis'alef (he faint and miss praying - Shabbos 9b).