Ash
vaporist
The koozie I use is is neoprene, like these:
http://www.beerkoozies.com/koozies/can-koozies.html
I cut of the bottom part and made a notch for the power cord. No offgassing with this one. I haven't tried the foam koozies, but they seem maybe less safe to me, and certainly less aesthetically pleasing. The neoprene is really nice to hold and doesn't add much to the diameter of the vape.
http://www.beerkoozies.com/koozies/can-koozies.html
I cut of the bottom part and made a notch for the power cord. No offgassing with this one. I haven't tried the foam koozies, but they seem maybe less safe to me, and certainly less aesthetically pleasing. The neoprene is really nice to hold and doesn't add much to the diameter of the vape.