I know hot yoga is sort of "in" right now but I completely understand why. It is such a great workout in a different way than a run will ever give you. You sweat, a lot. You use your arms, a lot. You bust your ass the entire time until you get to savasana.
Around here we have hot vinyasa yoga which is a flow type of yoga where you are constantly moving from one movement to the next all while you are in a 90+ degree room with lots of humidity. The reason for the heat is to get the sweat going along with circulation for complete detoxification.
I've taken a good amount of classes now and it continues to be hard for me. My arms are so wimpy and you use your arms for so much that it makes me still feel like it is such a challenge. I still have to look around at other people to see what they are doing but I am proud that I keep going. You easily forget how challenging the class can be when you sign up for another but are quickly reminded when you start your sun salutations.
Alicia and I went to a class last night and it was exactly what I needed. I left feeling refreshed, calm, and ready to take on the rest of the week. If you haven't tried yoga and are on the fence about going, I highly suggest it.