I would NOT recommend warming 1 cell LiPos. I thought I would try it when I was at Vegas. I left one of my SMC 4900's on the control unit of my Soldering iron to get it a little warm. I pulled it off and temped it at 128*F at it's hottest point and it had puffed a noticeable amount. It reduced a little after it cooled, and never separated the case, but its now raised a bit in the center . . .

Try it at your own risk . . .