I have Scarpa Phantom Tech, technical mountaineering / winter climbing boots. They are generally great but I'm experiencing a strange phenomenon: my feet get seriously cold when I stop moving, although they're supposed to be warm and cozy. Conditions were not Himalayan, they were more like 25-32F (-5 — 0C)! Worse: when I was testing them in my backyard in spring, I also felt cold while sitting at temperatures of 40F (10C)! Something is completely wrong since the boots are designed for winter climbing, where you might be motionless for prolonged periods of time (for example, while belaying).
When I take them off, the boots are completely wet inside because of perspiration (they're fully waterproof with built-in gaiters and a drysuit-style zip). I suppose the wetness causes me to feel cold. However, the manufacturer states they should be breathable. I was wearing trekking socks with merino wool, not cotton socks.
Am I doing something wrong or is it an expected behaviour?