Are you going to be able to crouch that baby bottle well enough to not look suspicious? Seems like a awful big bottle to try and carry between your legs... The required testing amount is only 2oz, but the tester may ask for a little more. I think the baby bottle may be overkill for you. If I were you I would go to walmart and find yourself a travel shampoo bottle(flat sided), some hand warmers, and baby thermometer strip that you can attach to the bottle. The hand warmers will ensure that the sample stays in temperature range. I don't think that the tin foil will be sufficient and could become quite noisy. If you decide to go my route, make sure that you wash the shampoo bottle out thoroughly before you add the urine.