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I'm glad that no-one was hurt, fried, toasted, baked etc.
I invested years ago in heat packs.
A heat pack contains hypersaturated sodium acetate and water. Sodium acetate is very good at supercooling. It "freezes" at 130 degrees F (54 degrees C), but it is happy to exist as a liquid at a much lower temperature and is extremely stable. Clicking the internal disk, however, has the ability to force a few molecules to flip to the solid state, and the rest of the liquid then rushes to solidify as well. The temperature of the solidifying liquid jumps up to 130 degrees F in the process.
When you boil the solid, you melt it back to the liquid state. You have to completely melt every crystal, by the way, or the liquid will quickly re-solidify. You can repeat this cycle forever, theoretically, just as you can freeze and melt water as many times as you like. The plastic pouch eventually wears out and leaks, though (since sodium acetate is a food additive, it is non-toxic). Mind you mine are now ten years old and still work well!
The heat lasts for a few hours or so. Much safer than 240 volts AC at 10 amps!
Got mine at Victoria Markets for $10 for the small pack (50X150mm) and $30 for the large pack (A4 size).
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