This product review is as good as it gets. The customer who bought Pedag Solar posted this review on Amazon.com.
“I purchased these insoles to go in my fire "bunker" boots. I work at McMurdo Station, Antarctica, and our airfields are on snow and ice surfaces. The steel shanks and toes in our protective boots suck the heat right out of your feet - so much so that most of my colleagues use "toe warmers" in their boots every shift! These insoles are spectacular - they're thin enough that they don't really change the fit of my boots, the insulation is comfortable without being TOO spongy like some insoles, and the aluminized layer keeps the cold out below and the heat inside my boots. I would recommend these without hesitation to anyone who has to stand around on cold surfaces for any length of time, especially in footwear that isn't designed for cold weather. I've already given a pair to a colleague, and he's as excited about them as I am.”
By the way, it you need orthotic support in addition to the warmth of Solar try Solar Plus which is identical but also has full longitudinal and metatarsal arch support and a heel cushion.