2 oz is all thats required but some of the fly by night outfits might try to get you to piss more.4 Oz should be plenty for them.

The thermos idea would probably work if you got the water the right temp and if you have time to do the switch.
Usually if you have access to a microwave its easier to just do that.
killerweed420 Reviewed by killerweed420 on . Bottle Size and a thermos Great site! I have a question â?¦. Iâ??m going to sub for the test. Most people on this forum use a 2 oz bottle. Iâ??m going to use a 4 oz. I remember last test I gave, I had to piss in a larger container, then the clinic person took that and poured the piss into a smaller container, which I assume is shipped out for testing. Does anyone know what the average size is for the larger container? I want to make sure that I bring enough with me to satisfy that first, larger container. Rating: 5