My hottest curry was in a restaurant called The Handi in Drummond Street, London (an excellent street full of curry houses near Euston Station) about 12 years ago. The hottest on the menu was a Vindaloo (already at phal- like temperatures compared to other places), but in a fit of bravado brought on by too much Guiness, I order the Vindaloo with a 'please make it hot this time!' comment.
Any they sure did, although it was still edible and pretty tasty. My companion that evening had a foot in plaster due to a skiing accident, but after eating the curry he claimed he couldn't feel the pain in his foot anymore.
The incredulous chef popped out of the kitchen to watch us finish it.