I had an out patient biopsy and drank coffee before leaving hospital. I was still out of it enough I didn't notice the coffee was scalding. I had blisters. I didn't sue but I called and yelled at various hospital administrators.
I was able to raise blisters on the lips and tongue of my best friend--it was from my salsa. I made it really, really hot.
She didn't sue me. She just asked for a warning the next time.