Ive even went so far as to tape a thermometer strip like you see on aquariums or on the actual test cup to my pee pee bottle...maybe not really needed but made me feel better.
i bought some actual test cups from ebay,, that have the thermometer on them,, and what i do is strap the carry bottle to my leg with the 6.1 leg strap i bought, and slap a hand warmer,, then wear it around for like a half hour ,, simulating my drive to the test facility,, then i go to the restroom, empy my pockets,, go in, and make the pants sounds, flip the toliet lid,, grab the carry bottle pour it into my real test bottle, then pee in the toliet,, good and long so they can hear it,,, then check the temp on the test bottle,, so far so good,, i did buy some baby bottle temp strips that work on the carry bottle,