Does sweating release toxins?

After practicing yoga in normal temperatures for years, I recently attended a heated yoga class (heated quite hot: 95 to 100 degrees!). The experience left me dizzy, nauseous, and completely enervated. Afterwards, I expressed my concern to the teacher, asking why the studio needed to be so hot. She "explained" that by sweating, supposedly the body releases "toxins" and that my nausea and dizziness must indicate that I need to "detox." Personally, I think I was suffering from heat exhaustion. I've heard this silly explanation more than once, as many people seem to believe toxins are released through sweat. But is that true??? And — next question — doesn't exerting oneself in extremely hot temperatures seem like a recipe for dehydration? Are their any benefits that make it worthwhile, or is all this heated yoga just nonsense?


Do I need to stay home from class if I have chickenpox?

I've come down with chickenpox. Should I stay home from classes even though 90 percent of adults have already had it and are thus immune? If I take great care washing my hands and avoiding coughing anywhere but into the crook of my arm, will I be reasonably assured of not spreading it?


How contagious is measles and how is it spread?

A friend of mine is living with someone who might have just got measles (results pending). If true, and my friend has also got it, how contagious is it? I think it is measles, rather than German measles, which I had as a child. Does past illness provide any defense? That is, can you get it twice? I presume having had German measles does not provide any protection against measles.

How is it transmitted? Like a cold? (Physical contact, common contact with hard surfaces, and maybe airborne?)


What is proper gym etiquette?

1) When you are at the gym exercising do you need to wipe down each machine that you use even if you are not sweating?

2) I'm looking for some helpful pointers you might have on the subject of health club etiquette (i.e., don't wear perfume because others will leave workout equipment wearing your perfume). I would appreciate anything you have to offer on the subject.