The Burton Synthetic Midweight Base Layer Pant wraps a next-to-skin fit around four-way stretch and a crotch gusset built for unrestricted movement, while HeiQ Smart Temp regulates temperature through changing effort. The tight fit stays out of the way under a shell pant instead of fighting the body through a stride or a deep bend. What Our Gearhead(R) Experts Are Saying:"I've kick-turned up a skin track in these without ever feeling the fabric pull or bind at the hip, even in a deep lunge. HeiQ Smart Temp kept me from overheating on the climb, so I never had to stop and vent a layer."