Theoretically, the hottest curry you could make would be a bowl of pure capsaicin crystals. This dish would be 10,000 times hotter than a vindaloo.
Although capsaicin does not actually cause a chemical burn or any direct tissue damage itself, the impact on the nervous system of such powerful stimulation is similar to an allergic reaction. As well as incredible pain, you could expect uncontrollably streaming eyes and nose, upper body spasms, and severe difficulty breathing for 30 to 45 minutes.
Provided you are healthy with no history of heart conditions or asthma, it might be possible to survive a teaspoon of pure capsaicin, but impossible to eat anything else for a few hours.
Theoretical limit: 5g capsaicin
Current record: 0.1g