I can handle heat, but I have to say the Ghost pepper (Bhut Jolokia Chili for those of you who don't know) is ridiculously hot. The heat creeps up on you. at first its no hotter than a habanero, but after about ten minutes it really sets in. These peppers are so hot, there is no reason a human should want to eat one. They are devices of torture.
I ate a bite of one out of a dare when I was on vacation with some friends on Oahu. The pain lasts for about an hour and a half, and you literally don't want to do anything. These peppers seriously will bring a six foot seven man to the ground. I've even heard they have sent people to the hospital.