"One such story was from a couple who were out of town when their furnace went nuts and raised the temperature in the house high enough that it melted every pie

"One such story was from a couple who were out of town when their furnace went nuts and raised the temperature in the house high enough that it melted every piece of plastic in the entire home." There's just no way that a home furnace can generate enough heat to do that. Sounds like scaremongering to me.