The best thing to do is get a clean sample from someone if the same sex, get a thermal mug and boil some water, keep the urine in a smaller container that will seal tight so you can put it inside the thermal mug on your way to the drug test. This will keep it above body temperature, when you arrive at the testing location take the urine out of the water and hide it where ever you can. It should stay plenty warm while you wait. Then when you go back dump the clean urine in the sample container they gave you. Be sure to look at the temperature before you give it to them. If its too hot still simply put the bottom in the toilet water to cool it down to where it needs to be. This always works for me