If the machine is on the verge of melting already, it's likely just going to hard-shutdown below the OS level. All this could really open them up to is a hard-

If the machine is on the verge of melting already, it's likely just going to hard-shutdown below the OS level. All this could really open them up to is a hard-shutdown, and I imagine they would have implemented this as a higher threshold, not a complete disable -- at least, it seems like a really easy problem to foresee and circumvent.