when you do hot yoga it is no joke. your mistake was leaving which defeats the purpose of it in the first place.. finish the class as much as it seems unbearable.
you need to make sure you are properly hydrated going into the class and during the class hydrate as well. i recommend mixing in some salt, cream of tartar, and liquid magnesium with your water to give you electrolytes from sweating so much
i've been doing yoga for almost 20 years now. Hot yoga is something that I've started to do a lot of lately and it is tremendous for improving flexbility. i highly recommend it, just find a good place.. not some old people yoga studio. a good quality hot yoga studio will give you much better results than regular yoga at your gym with some cookie cutter instructor. it is like comparing working out at the Y vs. a meathead gym