Been experimenting with these cheap heat pads you can pickup at a Dollar Store for a buck. They seem to work very fast. 5 minutes the QF is heated to 94, 10 mintes its heated to 96 degrees. The pads only heat for 30 minutes so they work well with randoms with no warning. The heat pads that come with QF seem to take up to about an hour to get the QF up to temp. I just break the seal,use velcro to strap the pad to the QF and stick it in my pocket till its time to go piss then I stick it in my crotch. Just another tool to help beat the piss cops.