There's also a recently opened yoga studio in Kenwood that offers hot yoga classes. Kenwood Hot Yoga is a little higher than some of the other yoga studios I've been to for their single class and pass prices, but, unlike other studios, they exclusively offer hot yoga classes. I haven't been there yet, but I've heard very good things about them, so they definitely are worth checking out.
I've taken yoga classes at several of the yogahOMe locations (they have three: Oakley, Mariemont, and Symmes). They offer a variety of yoga classes, including many hot yoga classes, especially at their Oakley studio. Some of the other yoga studios offering hot yoga sessions are Bikram Yoga Cincinnati on Red Bank and Moksha Yoga Cincinnati in Columbia-Tusculum.