I have had experience with electrical problems -- my dishwasher -- it refused to turn off, and it became quite warm by the next morning -- so I don't run the dishwasher just before going to bed -- also I don't leave the dryer running either just before going to bed or start the dryer and leave to do some errand -- having experienced the loss of our home and almost all our clothes when I was about 9 or 10 --I still haven't forgotten that. There are cords available with inline switches to turn off the power -- to your iron or any other appliance.
Thank God you were at home and right on the spot, so to speak, to take action so that you weren't burned, nor was your home.