Temperature a big issue in Urine Drug Test?

[svica]

Hey, been looking at options for self-done drug tests and just read about the urine needing to have a certain range of temperature in testing. Just wondering if this is a big deal? I mean, how about you do the test in an extreme temp? Btw, I've read about it here: https://testcountry.com/blogs/drug-testing/how-to-read-a-drug-test-cup.