Drug Testing Question

If my brother, who has clean piss, pisses in a bottle and i keep that urine at room temp for two days until the morning of my test, it would still be good correct? i plan on strapping it to my thigh the night before and sleeping with it like that so it becomes body temp. that should work correct? i've done something like this before but i don't think it was two days. it was the day right after i think. i plan on transferring the piss to a large visine bottle and then strapping it to my thigh.

i'm worried the test won't read correct if nots body temp. that's why i plan on keeping it on my persona over night and through until my test.