For treestand sitting in real cold weather is what a heater body suit is meant for..not my ground blind with my heater, lol. $300 for the heater body suit and $400 for a canadian similiar item called the cocoon. All they are is sleeping bags with feet and they nail a huge price tag on them. I like to make and invent and am noyt afraid to spend $$ on the best, but it just seems way over priced for a sleeping bag imo. Thanks and I am pming you my ph numbers. I will look at AT in the homemade threads you told me about..thanks.