i hear ya. i’m sick with a head cold right now and will have missed about 5 days of yoga. however, i’m pretty sure it’s not the yoga that’s the problem. i was actually marveling for a good couple of months how i was NOT getting sick and was attributing it to the yoga. i’ve heard that this kind of yoga is great for repelling and squeezing out these toxins that cause colds/flus. i’m pretty certain my current cold is a result of being around people in my non-yoga life who have colds. so, not speaking from a scientific background, i’d say hot yoga is a cure not a cause but i could be totally wrong.