To keep it from leaking during those altitude climbs, if you can, take the tank off and put a small wadded up piece of paper towel where the drip tip goes. Set it in something that will hold it upside down consistently. That will keep the liquid in the tank and not all over the place.You may be right there, Robin! Since moving to other tanks, I do tend to have the coil sitting pretty close to the airhole. I did notice the heat thing and altitude in travel. I brought one with me on our last trip here, and there are lots of big climbs on the journey. The tank pretty much emptied itself all over my Provari. Thankfully, I had it in a ziplock bag.
I take the drip tip off, wad up some paper towel, shove it in the drip tip spot and place the whole thing (ProVari and kayfun) upside down in the side pocket of my purse, when I fly. Totally stops the leaking.
