Believe it or not hot yoga is a type of exercise people are practicing on such a high scale that it is becoming a craze. Hot yoga is a combination of different poses carried out in a special heated room of which the temperature is normally between 95-100 degrees.
The usual lightweight clothing, anti-sweat athletic wear that dries quickly will do just great. For men its light tees with shorts and women can wear a tank top or sports bra with shorts or lightweight pilates memphis yoga-style pants.
Imagine, Richard Simmons working over a group of oldies looking like they just walked out of a shower and forgot to take their clothes off. I would definitely recommend wearing loose fit, sweat absorbent shorts they should provide some extra breathing room.
Commune as much as you want in the reception area...but once you enter the yoga room, silence is the mantra. It pays to start your practice peacefully. I recommend you lie on your spa haus body wash mat and fill your mind with things that feel good to you; let the heat bake those good feelings into your limbs. Really. So - zip the lip in the yoga room and open your heart to... whatever you want.
I discovered yoga by chance in the bookstore. I stumbled upon Beryl Birch's "Power Yoga" book. I was interested because the hot yoga routine was extremely physical. I did Power Yoga for a number of years while weight lifting (sometimes I'd take a break from weight lifting).
If you're concerned about not being able to perform some of the poses, don't worry. Most poses have varying degrees of difficulty and can be easily modified for beginners. Often, the instructor will be available to show examples of modified poses and to help you get into proper position.