I've actually lost count on how many classes I've taken now. Probably 9 or 10. I had been averaging one class a week (and then..no excuse why I didn't go last week). However the last class I finally had adjusted to the heat. I could actually move after class and didn't feel light headed for 20 minutes after.
Now that my 1 month membership has expired, I'm not sure how often I'll be able to afford to go. My goal would be once a week. I do feel like it's great exercise and very, very challenging. The only downside is that it takes so much freaking time for one class. It takes me 20 minutes to get there and you need to be 10 minutes early to get a spot for your mat and adjust to the heat. It takes me another 15 minutes to cool off in the locker room after class and the class itself is an hour and a half. So it's over 2.5 hour comitment in the evening plus having to deal with sweaty clothes and towels and mat after.
This shit is hard yo!