Hi.
I agree to what Robert said. Swimming pants would be the best but I sometimes get allergy reactions from the fabric. I use cotton. Best is organic cotton for me. Yes, it gets soaking wet but I don´t mind really. Hot yoga is like swimming anyway. Interesting topic by the way. I´ve found an interesting Swedish brand called b-light. They have organic stuff. I have the Kam shorts shown here for hot yoga: https://b-light.se/organic-clothing/men/bottoms-yoga-sportswear/shorts/
I have not seen if they also sell women’s clothing.
Namasté
Buddha