An autistic response to stress or sensory overload, in which the person is overwhelmed by intense, seemingly disproportionate emotions, behaving erratically and becoming unable to mask.
A tantrum or emotional outburst.
Severe overheating of the core of a nuclear reactor resulting in the core melting and potentially in radiation escaping.
A situation being likened to a nuclear meltdown; a crisis.
Computer engineers were at a loss last night to explain why the Government had been hit by arguably the worst electronic meltdown in the history of Whitehall. https://web.archive.org/web/20041209011615/http://news.independent.co.uk/uk/politics/story.jsp?story=587262