Or if your like me and like to make things difficult.... Get a small cooler, and a peltier cooler.. Mount the peltier in the cooler, grab a micro controller of your choice, bang out a quick code to keep the gun temperature around 80 degree's ( it can heat, and cool ).. Plug it into a 12 volt power source and your done
I like to make things difficult, although I dont have the need for anything like that, if I did I'd rig something like that up... If there was a demand for it, I could build a few ( but it wouldnt be cheap )... A gel pack and a cooler is a lot simpler to do...