Using Cold On Your Balls (Possibly NSFW)
Last year I spilled some hot food on my crotch area (everything down there is safe).
During the "healing" process, I used an ice pack in the area and discovered that cooling the man region actually made changes to my overall body.
It is essential for male reproduction to keep the testicles cold, but it has many benefits for overall male health (I will have a post on cold thermogenesis in the future).
Showering in cold seems to have a different effect, as this biohack is location specifically 😉
How To Do It
When I do this, I notice a sharp increase in libido and significant nootropic-like effects on cognitive performance.
I also like to do this in the Sun and allow the natural infrared to touch my junk (if you incorporate this, make sure they do not get too hot as that can be potentially damaging).
Cold thermogenesis has shown to increase testosterone and Dopamine levels, so this could be one mechanism for it.
Don't over-do it.
I don't know how this effects those without testicles.
Don't be a dick.