I live in Minnesota in a 1920′s house with newspaper for insulation, and have not been able to get rid of cold feet — until now. These insoles are the same thickness as normal shoe liners but they have an aerogel in the sole. Like normal shoe liners, these come over-sized, so you cut them down to your shoe size using the templates printed on the soles. I have used them while wearing several different styles of shoes from dress shoes to work boots to tennis shoes to mukluks and ice skates, and have not noticed them shifting inside the shoe.
I have noticed a little bit of compression after wearing them 12 to 16 hours a day for two months, but I have not noticed a difference in thermal performance. On my wife’s pair the insulation layer has started to separate from the padded layer and she says they do not make her feet as warm as they did when she first started wearing them a couple months ago. But she shifts them between shoes much more often than I do. These insoles are cheap enough that you can buy multiple pairs and avoid moving them around, which should help maintain their integrity longer. My pair looks like it will last a few more seasons and I plan on taking them out when temperatures get above 10 degrees or so.