advice please for a new irish member

ok i gave up pot for 26 days cause i have a really important drug test for a job tomorrow...drank lots of water however i still tested positive for a a home drug screen i took today....so im assuming i wont be negative in the next 24 hours...
my friend is willing to piss for me however ive gotta go throw an airport so will have to leave it in my bag for 1to2 hours before i can put it in my crotch..ive read n2's advice on substituting what im wondering is will having it in my groin for 2 hours bring the sample back up to body tempature?? (crossing legs and everything)
by the time i take the test the urine will be less then 5 hours old....
or would i be better to try diluteing my own urine??
any advice would be greatly appreaciated as its a family memeber who has arranged this job for me and i really cant fail...(26 days and still positive ffs obviously im a pothead and gutted)
this is my first post..
any help?

ok edits here........
will having the urine container in my crotch for 2 hours take the container up to body heat level.....any help would be very useful as im running out of time.....ive found a container im comfortable with......would i be better off placing it in a cup of coffee to heat it up.....
anyone.....please?
advice needed asap

go to a camping or sporting goods store even wall mart, and buy a couple instant handwarming packs, thay are called hothands by heatmax

you can also find a medical supply store and by a coloctomy bag and put your urine in it, and attach a heat pack to one side of the bag!

ok i really thank anyone that has replied to my post....
my main problem is that i only have 10 hours till my test(2 at the airport)(different timezone)
not sure if ill be able to get the products ye mentioned....(aww shit)...
would a heater in the airport toilet work?(desperate)...
gonna crotch it at the first chance i get...
again thanks...
but any advice??
or even recommendations/experiences....
cheers.....
will let ye know how it goes
wish ,me luck....