I couldnt agree more about safety switches, i have one that triped, strangly the day after first reading this thread....... took me some time to find what was wrong where in the house and i tracked it back to a heat mat under a snakes pen, i have attached (i hope) a picture that i took of the mat after removal, this was on a timer to only run durning the night and on a thermostat so as not to get too hot, and it only got to a max of 28deg anyhow acording to the packaging. mmm was i impressed, safety switch well worth the few hundred dollars in my mind.
cheers
chris