Shots from Samus’ frosty firearm are so cold that upon impact they causes their targets to become instantly encased in ice. So how exactly do they manage to get out of the barrel the weapon without freezing the inside of it solid along the way? If the ammo is cold enough to insta-freeze at distance, surely it’s even colder as it leaves the gun.
Indeed, given that metal has particularly strong temperature conducting properties, using this thing should freeze Samus' whole suit up, or at least chill it to the point of severe discomfort, giving her an instant full-body brain freeze and goosebumps you could grate cheese on. Yes, the heat-insulating Varia Suit might also protect Samus from cold, but consider her armour’s metallic outer materials. Consider the effect on their integrity if using the Ice Beam immediately after the flamethrower or red-hot Plasma Beam. Seen Alien 3? Yeah, that.