The leg warmer concept seems to have ended up as a funny 80’s footnote, a bit of joke clothing, used by dance instructors and ballet divas. Really, just as wristovers and arm warmers are a fantastic idea, allowing you to fine-tune your insulation, so are leg warmers. The ones featured here are Swedish army leg warmers, designed to both create some form of seal over the tops of your boots, as well as increase warmth (when worn under your trousers). The use of some warm thermal pants, and a set of power-stretch leg warmers, that can be pushed down around your ankles on a walk in, but pulled up, perhaps over your knee, once things slow down, might be better than wearing full thermal underwear.
One of the best uses of leg warmers is for very cold, or sub-zero rock climbing, where you’re forced to wear rock boots where you’d normally be wearing insulated double boots. Here, you want a leg warmer that covers your calf and ankles (usually under fleece and shell bottoms), in order to have as much insulation where you can get it (I seem to remember Leo Houlding being a leg warmer fan). Ideally, such a cold weather ‘alpine’ leg warmer should be sewn up so it can be pulled down over your boots to try and stave off the hot aches (but they will come). They can also work a little like gaitors (you will have socks on hopefully), pulled down around your heal if you have to cross some snow patches (BTW rock boots are NOT very sticky on ice or snow). Of course, such an item is great for milder winter climbs as well, is should probably a standard item of clothing for winter craggers, but I guess they’re not because who wants to look like an extra from Fame?