From 8 AM to noon Wednesday, Maxine Salon will give away free 15-minute Kerastase Paris hair treatments at its swanky River North store (712 N. Rush). What Kerastase does, exactly, is anyone’s guess (l’Oreal’s Web site calls it la sublime metamorphose” of the hair), but the sessions are valued at $100 and come with a consultation, head massage, and blow dry. Just print this coupon and bring it in with you. Free snacks will be provided by Corner Bakery.