Comment by static_motion

What are you on about? Your premise is pure bunk. The metal doesn't glow in normal usage. Speaking from experience: if that happens, it's a terribly painful experience and nobody would enjoy it. Vape coils usually heat to under 205°C/400°F, enough to transform the liquid into vapor but far below the glow point of the metal alloy typically used (kanthal/FeCrAl or nichrome/NiCr). Replacement is necessary due to residue buildup from the liquid, not because the metal has become degraded.