I learned to never leave any appliance running unless I'm at home........inside.........and awake. My dear Mother taught me that. I questioned whether that was really necessary until one day, I went to hang the clothes from the dryer (this was before signals), and the dryer cabinet was so hot to the touch it's a wonder it didn't melt! DH was at home that day, unplugged it, took it apart, and the cut off switch had failed to activate. Had we not noticed, it would have definitely caught on fire within the next few moments. So grateful that we were at home, and even more grateful for my Mom's advice!