The act of growing a pair & wrecklessly entering dangerous situations.
Made popular by the show Breaking Bad where Walter White starts to become more of a badass as he delves further into crime & the drugs market.
Example of To Heisenberg include
Telling a 6'5 giant bald guy who would rip your face off to ''stay off my territory''
Blow up a building with your awesome chemistry skills
Do a long con on a major drug-lord
Set a car on fire whilst the owners back is turned
Run over drug dealers & shooting them in the head if they survive