I myself am not a huge fan of yoga. For me it's incredibly difficult on my back. So I gave hot yoga a go. I loved it, I was able to set myself into the poses. My back was co-operative, until two days following.
Hot yoga is a very touchy area, because the heat helps to open up muscles and tendons people tend to over stretch. which in the end causes injury,
Okay so that aside. People have been lured or attracted to hot yoga for one main reason, detoxification. In 2005 the Center for Disease Control preformed a study on 2000 people and the research showed that the average person contained approximated 60 different types of toxins in the body. YIKES! This sparked the hot yoga trend.
There are two types of sweat glands in the body.
Eccrine - these glands are located all over the body and their primary chore is to regulate temperature control.
Apocrine - These are located in specific areas including the armpits and naval. These are activated by stress or stimulation. Apocrine has a few additives like protein and fatty acids.
However, sweat is made up of mainly water, sodium, chloride and possibly potassium. As far as toxins go, trace amounts....about 1% of sweat contains toxins. So if your looking to hot yoga for detoxification unfortunately 90 minutes in a room at 41 degrees is not going to detox the body. The kidneys and liver are the filtration system for toxins. Not sweat glands.
In fact, sweating to those levels can cause dehydration, which can cause kidney failure. So if you really enjoy your hot yoga, make sure you have on hand a ton of water. Make sure there is no shortage.