I used Toe Warmers last week in the Catskills. It was 10 above one day and they worked fine. I put one set on the tops of my socks and another set on the bottoms. They lasted for about five hours. I was wearing polypro liner socks under medium weight wool socks. One of my hunting buddies had electric socks. He said they were great. He had a wireless controller for them, so he could turn them off if he got too hot.
The expiration date on my Toe Warmers is 2/2020, so they may have lost some potency. The last time I used them was in 2016, when I bought them. I remember they were hotter then, and I only used one set, on the bottoms of my feet.
My boots are Cabela's insulated leather which I bought for last year's hunt in Colorado. They worked fine without Toe Warmers in Colorado as I wasn't sitting on a stand all day, I was walking.
