5 star product, 4 stars for price-to-use ratio.

Do NOT buy this as a serious outdoor thermal. This is for casual outdoor or indoor use. The silk has served my needs for my winter drives to work and cold office. The silk is comfortable and don't get overhot indoors or while moving around a bit. But if you want superior outdoor insulation go get some polypropelene thermals.

Downside is that these are not cheap, and I don't think they will last long because they are thin and delicate. So price to use is not great.