one of my friends actually had to move his computer from a case to a cardboard box. he couldn't fit a proper cooler in his case and couldn't afford a new case so he put it in a box
The heatsink on my old pc got so hot we left a piece of sausage on it while we went to school. It wasnt cooked but the skin was burned off and all the grease had come off and stained the aluminum.
My cpu was happy to run around 125 degrees celcius, Not joking.