AeroTherm Flat-u

I used a block of ice and compared the insoles from my new Shimano SH-MW81 SPD Winter Shoes these Aerotherm aerogel-infused insoles from Amazon, and there was a significant difference in heat transfer.

I bought several pairs of thermal insoles (Spenco Warm Air, 3M Thinsulate, Superfeet wool) and then compared them by putting different brands in each shoe. I originally thought that the Superfeet wool or the 3M would be the warmest, but I was wrong, these AeroTherm were the warmest out of all of them. The 3M Thinsulate ones came in a close 2nd (then Superfeet). The Spenco Warm Flow's are no longer made and I would say those are meant for runners in cold weather.

These are very comfortable but both pairs I purchased split at the seams and let silicon powder (I assume) invade my socks, repeatedly. Won't buy again.

Bigger than my foot, but since I ordered a boot bigger than my foot, to insert these into, cuz I'm tired of cold feet, it wasn't a problem! I thought they even be too big for the boot, but they "snugged" right in...