I went through the same experience once; instead of 1-10 I told them I wanted the "Thai spicy" maximum. I thought being an Indian it should be something I could handle; I couldn't have been more wrong. That thing burnt my intestines and "exit wound" was literally true. Took two days to feel completely alright.

"Indian spicy" is not really that hot - it's more about the strong flavor that comes with mixing spices of multiple varieties.