Keep Quick Fix in your pocket at all times if you're really concerned. I used it recently to pass a test and I'm now one of it's biggest supporters. Being in your pocket probably won't keep it between 90 and 100 degrees, but if you can stall for a bit and get the heating pad on it it will get warm enough pretty quickly. There are full details on how to use the Quick Fix elsewhere on this board. Otherwise you just need to quit smoking, which do you prefer?