This is interesting because I never really imagined that a there was that much of a temperature rise on a fuse or circuit breaker. I've heard numerous stories of "hot CBs" but just how hot has never been put into numbers.
A little anecdote: Based on what I've seen here I did an improv test where I found a small 2A fast-acting cartridge fuse. I ran it at about 2.05 amps AC for ten minutes, and sitting in free air it got up to 122 degrees as measured with a little wire thermocouple. I could see the fuse-link elongate and bow with the heat, but it never blew.
-John
