I have a pair of the old jon-e hand warmers. I know they are over 25 years old since I have not used them for that long. Still in the red bags. I have some insulated camo cushions that clip onto the back belt loop. They retain heat really well and no fuel required.
Patron Member NRA
"I would not be an old man if I had not been an armed young man." JTJ
I was taught to respect my elders but they are getting harder to find.