I have a drug test coming up in less than 24 hours, my friend is coming to pee in a cup for me in a couple hours and I planned to ziplock the urine. Now, to clarify this, is it safe to have EXPOSED urine for a 16 hour timeframe without it being rejected in a test? And, what is the best detailed method to make sure the urine stays at the right temperature?

Currently, I understand taping the bag to your armpit or between the balls and hole is a way of keeping the urine at a good temperature, your thoughts?