Yeah, I did not have to retest.

And no, I've never had temperature issues. I've substituted my samples every time I've had to test - which is no less than 25 times in the last 5 years (what can I say? I tend to arouse suspicion). Plus, I advise my friends on how to successfully carry samples; and they've never failed. As long as you keep the sample wrapped or pressed against a hand-warmer you can keep your sample at or above 100 degrees. Most temperature strips utilized by the lab techs don't register above 100 degrees, so I don't worry about the urine being too hot. The hand-warmers I often use are Coghlan's disposable hand warmers ($2.99 or so at RiteAid) which average 140 - 155 degrees Fahrenheit (according to the package). If you use a hand-warmer, make sure it lasts longer than two hours. I have found the ones that claim to last for ā??up to 2 hoursā? noticeably cool down after about a half hour.

I use prescription pill bottles (the orange ones) as my containers of choice. I use these because they don't leak, they are easy to come by, and they are small/skinny. Also, even though the amount of urine they can hold is a little on the less side, I've never had a problem. For the bigger sample-collection cups used by lab agencies, even the small amount of urine in my pill bottles is enough to reach about halfway up the temperature strip, and therefore be "enough" (because the temperature is still registered). Even though the technician marks how high up I am supposed to fill the cup (and I rarely ever make it to the mark), I just sheepishly say, "That's all I can manage." One time, though, the urine was well below the temperature strip so I suggested the technician tip the cup a little to register the temperature. He was not impressed, but tipped the cup anyway and went about his business.

Edited to Add:
If you merely press a hand-warmer against the container, make sure the container is pressed against your skin or something equally insular and warm.