On heat and practice...
I recently read a great Facebook posting by certified Ashtanga Teacher and author Gregor Maehle on the subject of heat in the Ashtanga room during practice. While I find the preference of a hot vs. cool room depends on one's constitution (i.e. whether or not your primary dosha is Vata, Pitta, or Kapha) in general, keeping the room at around 80 degrees F in New England seems to work best for most of our practitioners. But, Gregor gives some great insights on heat in the shala, and also, why it may not be necessary to keep the windows shut, too. Read on...
"I keep receiving questions regarding whether it’s important or good to heat the yoga shala and whether this aids in detoxing. I also hear people reasoning that the shala should be heated to emulate the heat of the gangetic plains in India, which is supposed to be the native environment of yogis. Now during the 1980 and 90’s I travelled extensively through the gangetic plains but I must say that I found them surprisingly bereft of yogis. On the other hand if you went up into the freezing Himalayas you found that the yogis were stacked up to the rafters. Surprising, isn’t it!
Do you remember that even Krishnamacharya went up into the Himalayas to practice tummo, yoga of inner fire, while sitting on the ice? You can’t practice that down in the gangetic plains.
Nowadays Western yogis are really emphatic about keeping the windows of the yoga shala closed. I remember that neither KP Jois old shala in Lakshmipuram nor the Parakala Matt in Mysore where T Krishnamacharya taught ever had any windows. And I remember that in January at 4.30 AM I always froze in those drafty windowless rooms. And nobody offered to turn on any heaters because there weren’t any!
Now of course in many places in which people practice yoga today it gets much colder than in Southern India in winter, such as North America or middle and Northern Europe. In which case it makes sense to heat the room to room temperature, say around 20 to 23°C (68 to 74 °F). Everything above that would mean that if you practice vigorously, the bodies cooling mechanism (sweating) would fail, which can be noticed when the sweat starts to run off and forms puddles. People who practice in such a fashion usually age prematurely and if you look at them 10 years later they have a washed out and drained look to themselves because of all the prana they lost, by practicing too vigorously under too hot conditions.
Notice that the yogis were very concerned about loosing tejas (inner glow) and one of the ways of preventing that is to rub the sweat produced during pranayama back into the skin. This is a technique, however, that should only be used in the context of pranayama and not during asana, during which excessive sweating should be avoided. Hence, do not heat the room too much and if it’s warm outside keep the windows open. Many yogic texts (shastras) state that the shala should be well aired. Hope that helps, Gregor"