I've been trying a few different solutions to keeping my feet warm in camp these past two winters. I started with just wearing thicker socks (not warm enough), then two pairs of socks (restricted blood flow which lead to cold feet), fleece slippers (not warm enough), followed by Needle Sports's Pertex & pile over-socks (good at drying damp socks but terrible long, narrow fit), over-engineered synthetic filled arctic camp boots (far too heavy) and simple pile hunter's socks (again good at drying damp socks but lack insulation). So the search was on for something more suitable.
I first read about Integral Designs Hot Socks on Backpacking Light's genuinely brilliant three part guide to Lightweight Footwear Systems for Snow Travel. If you haven't read these articles then I strongly suggest you make time to sit down with a cuppa and give them a peruse. A subscription is required but these are the kind of articles I pay my BPL subscription for. In-depth and well researched. Part 1 deals with Principles and Techniques for Keeping Feet Dry and Warm. Then Part 2 looks at the Components of a Lightweight Footwear System and finally Part 3 shows various Model Lightweight Footwear Systems for Snow Hiking, Snowshoeing and Snow Camping. More recently Phil shared his thoughts on lightweight winter footwear here.
Design and construction:
The Hot Socks are constructed from a Pertex shell for water resistance and breathability. They have a Cordura sole for abrasion resistance and a stretchy fleece panel running down the back that makes putting them on and off a breeze. There is a soft fleece cuff and the lining is a nylon taffeta that glides easily over even the fuzziest old wool socks. Insulation is 4oz (113g) Primaloft Sport offering 1/2" or 12.7mm of loft.
Fit & weight:
Normally taking a 10.5UK size shoe and knowing I'll be wearing big fat wool socks in the depths of winter I went for the XL size and they fit great. One point I'll make here is that anyone over maybe size 12UK might find them a bit tight so you might want to look elsewhere. They weigh 148g for the pair.
Even on winter trips I often only use two pairs of socks. When I get to camp I'll slip off the socks I've been wearing all day and put them in a pocket close to my body to dry out as best they can. Then I'll simply slip on the other pair of wool socks that I've been drying in my pocket all day and layer the Hot Socks over the top. The Pertex shell and Cordura sole should offer enough water resistance for short trips outside the tent but I'll probably carry a pair of 30g Tyvek industrial shoe covers just in case. Lets hope the Hot Socks help keep my tootsies warm this winter.