Scoville scale was created in 1912.

a jalapeno pepper on the scoville scale measures from 2 thousand - 10 thousand

The Scoville Scale

There is a "Scoville" scale that measures heat units. The hotness of a pepper is derived from the amount of the active ingredient capsaisin that it contains. Personally I like hot pepppers and can consume everything up to habaneros (with food). Beyond that, if there are any hotter, that's too much for me.

Scoville Heat Units

See related link below for the Scoville Scale