Is Hot Yoga real yoga?

“Hot Yoga isn’t real yoga” someone said to me in passing the other day. Humm…I thought. Here's a  question, what is real yoga?  Even the ancients don’t agree on what yoga is.  They speak of the yoga of Bhakti, of Jnana, of Raja, of Karma of Mantra or Yantra.  They even speak of Hatha.  [...]