Yes, the room is intentionally heated to about 90-95 degrees and in some studios, even hotter (Bikram studios will be around 105). While it is true that the heat is not necessary to practice yoga, it is absolutely safe and, in fact, has many benefits.*
Here are a few examples:
All that said, the heat will effect people in varying ways and caution should always be exercised. The heated room is a tool and not something you should have to survive against. Always listen to your body and take care of yourself. Proper hydration is essential before, during, and after class. As the sweat rate increases in a hot yoga class, body water loss increases, and without adequate fluid replacement, the body’s ability to dissipate heat is compromised. Electrolyte supplements like Ultima Replenisher are also helpful, especially when beginning a hot yoga practice and acclimatization process.
One final note, I have found that reminding myself of the benefits that the heated room brings during a difficult part of class completely shifts my energy and I am able to push though those layers of self doubt. It is my hope that this information also helps you in your personal practice.
What to Expect at Your First Hot Yoga Class
What is Hot Yoga and How is it Different From Other Yoga Styles
Thanks for reading!

*Practicing yoga in a heated environment is contraindicated for people with Multiple Sclerosis. Always consult your physician before beginning any exercise regimen.
(ref. "Physiological Concerns while Exercising in the Heat " by Leslie S. Funk www.wellness-design.com )
Lindsay, Great article! I have not attended and yoga classes as of yet but this was great information for any exercise routine. I am eager to get started.
Hi Debbie! Glad you enjoyed the article (I enjoyed writing it!). I will hopefully be posting some instructional videos soon as well. Stay tuned ….
san diego yoga…
If you are pregnant, your body undergoes changes each day. While a pose may feel wonderful today, it may not feel too good some other day. The most important thing to keep in mind while exercising is the principle common to all forms of yoga, which is …
Great article, Lindsay! It makes me want to take a class right now.
.-= Salt´s last blog ..I didn’t know they had a cat… =-.
Thanks, Salt, for stopping by! Happy yoga-ing!
Hahaha…great post. Reminded me of my first<a href="http://www.stress-freeliving.com/Yoga-Exercise-Products-s/1.htm">Hot Yoga</a> class, I had the same experience,
way over dressed, left over eye make up from friday night partying, not to mention a
hangover. No idea what was I doing in a Hot Yoga class! But somehow, I fell in love
with the torture and have been bringing my arse back to the hot room for over 2 years
now. Enjoy your next class!man can feel hero for hot yoga practise.so made film for hot yoga.