I’ve built a few of those back on the icefields, but I don’t rely on them for heat, just for insulation. Layer the ice with a thin tarp or a fleece between, keep the walls thick enough to hold the pressure, and make sure the entrance has a small, angled opening so the cold drafts don’t blow directly in. It’ll keep you warmer than a bare block of ice, but you still need a fire or a heat source if you’re planning to stay long. It’s all about balancing thickness, airflow and a bit of insulation, so don’t forget the thermal blankets for extra safety.

I keep the walls thick, around thirty centimeters if I’m using fresh snow, and I add a cross‑strap of heavy rope or a strip of plywood between the walls, right at the high‑stress point, to hold the structure together. I do a shallow thaw at the bottom, just enough that the ice can flex a bit when the wind shifts. The heat‑pipe trick works well; I run a copper tube from the stove through a sealed tunnel and back into the shelter, it keeps a low‑grade draft that nudges cold air away from the entrance. For the angled opening, I stack a few boards and a sheet of tarp in a V‑shape, then tuck a piece of old fabric under the base to block sliding snow. That keeps the seal tight without needing a huge windbreak.