Sweating with a spray tan?

I just started spray-tanning after years of tanning bed use. Once I found a great salon who's spray tan is reasonably priced and looks great, and lasts a little over a week-I was sold! I know theres rules about not showering/sweating for 8-12 hours after a spray tan and I always do my best to abide by such rules, and my tan looks great after my first shower. However, I live in NC and in the summers, it can hit 90-100 degrees! The past 2 times or so, even after my first shower, if I sweat, (which is inevitable in 90 degree temperatures) my tan is rubbing off onto clothing. This sucks! Not only do I not want to wear white because it'll stain, but then I have splotchy areas of skin that arent as tan as the rest of me! Anyone else have this happen to them? Is there a way to avoid it!?