Practice with water. If you can keep the temp, you are good to go! I practiced (and stressed) for days before my test. Luckily for me, I had a place to stash the QF and it maintained the temp no problem. I don't think you have this option. Read the posts on how the guys did it. Some post that it will keep its temperature for a couple of hours while crotching it. (without handwarmers). If you go get a little shampoo bottle (or condoms, if you want) and use your digital thermometer and practice with water, you'll know if you need to buy something additional to keep it warm. I found you could get your 100 degrees easy from the tap...no microwave required

Practice.