Well, he does live in Nevada, but the plug wasn't really doing its job. It's job is to plug the core hole left in the block in the casting process & keep the coolant in the water jacket, not to pop out when things freeze. That's just a side effect.
I can't help but disagree. The core plugs are there to plug the holes from the block casting process but they are also called frost plugs that will pop out when water freezes and expands in the coolant passages. From Wikipedia:
Freeze plug
A true freeze plug is an expansion plug located in the side of an engine block that is supposed to protect the block against freeze damage. Water expands when it turns to ice, and if the coolant does not have enough antifreeze protection it can freeze and crack the engine block. The freeze plugs (there are usually several) are supposed to pop out under such conditions to relieve the pressure on the block.
There is also an explanation of a "core plug" which is one and the same.
