i did a test run last nite and the temp went from 98.1 to 93.2 in bout 15 min with the vial up against my leg the whole time.(i was planning on having it tapped to my leg near my knee win i go test under lose pants) i guess if i have it under my jewels it would stay warmer but problem.. i will have too piss BAD if that warm vial is there for 20 min while i wait to take the test. should i go with a heater on the vial wrapped round my leg or no heater in stick it up by my jewels. ps it got cold last time win i wore 2 pair underwear and had it between them(the underwear that is).