THC, using someone elses piss

I just got a job as an apprentice electrician. Would've been great news if I didn't take 2 hits of weed last night. I have a friend with 'clean' piss, how would I go about making sure it stays fresh to use on monday?

 

fuckin strap a few heat packs around ur waist and put a dropper with the good piss in there nice and tucked in so when u drip it in it will be warm. there is no such thing as room temp piss since ur body temp is 97* F... and if ur being watched pissin in a cup then ur sol