After all, a scientist like Dobie just sees a sample in a test tube. There’s no test to match the piss to the pisser. “If you can just tape some kind of test tube with a friend’s urine in it to your thigh so it’s about as warm as your natural body temp, then you’re going to pass,” Dobie says. However, it’s not the easiest thing to pull off. Some tests are preceded by a pat-down and others are literally observed (read: someone watches you pee) by the test administrator. Many samples are immediately checked for temperature. There are products available to deceive monitors in the case of an observed test (read: a fake penis that dispenses a clean urine sample) and they’re available online.