Okay, so heated carbs not certified. I see.
the warmth just prevents ice from forming.
Actually what I understand is that the ice still forms (after all, the drop in temperature due to the venturi effect and evaporation of fuel is still there) but it cannot stick to the carb walls. So it either melts when it hits the walls, or is simply sucked as ice into the cylinders - where it evaporates real quickly...
However it's a very minor technical detail. The net effect is the same.