I almost set fire to my own trousers whilst wearing them. Seriously.
At school, I put a PP3 9V battery in my pocket which I needed for a metalwork project I had been working on. I was sitting in a classroom with the sun shining in the window on me and I could feel the heat on my leg and thought that sun is really warm. Then I could smell burning. And see smoke coming from my trouser pocket. A coin that was in my pocket had shorted across the battery terminals.
i did once set fire to my trousers while using a grinder . i thought it was getting hot with sparks flying , looked down and they where flames coming up my legs . lost the front of my trousers up to my knees by the time i could put the grinder down and pat it out . not to burnt yes very red shin like sun burn