heat, cpu's and errors

Factual Questions
1

I am not much of an overclocker, but I was wondering about heat and errors on chips. I have heard that one way you can tell if you overclocked your chip too much(and that it is getting too hot) is that the computer will freeze up often. What is it about the heat in a chip that makes it have errors? Obviously if it gets too hot it will burn up, but what is it about moderately too much heat that causes problems?

There are only two possibilities that I can think of. Could the heat cause the bits in the cache to flip somehow or could it cause the materials in the gates to change electrical properties and conduct when they are not supposed to? Thanks.

2

Higher temperatures raise electrical resistance, meaning weaker signals inside the chip. IIRC, it also makes it difficult for transistors to operate. Bear in mind, the chip also has a finite lifespan, and the hotter it runs, the shorter it lives. Every 10C increase in operating temperature halves the CPU’s lifespan.