The hot that's in different peppers is the same stuff. You get more of it in habaneros than jalapenos. Habaneros are right at the top of the list for hot. If there's anything hotter it just has a little more of the hot in it.
After eating hot stuff your senses are dulled down & you don't notice the hotness as much.
There is an area in Mexico where the people eat nothing but habaneros made into a paste & then spread on bread. It's common for them to die as young as 35 when their stomachs burn thru & they bleed out.
Sounds like fun
