Heat therapy - full body vs penis only

[Asphyxia]

Are things like sauna, hot baths and dressing with warm clothes superior to heating the penis only?
Do i even need to keep my body warm?
What if i put heat on my penis while my body is cold?

Blood viscosity increases 2% for every drop in core temperature of 1° C
This leads me to believe i need to keep my body warm but im not sure.

[Brow]

Heating only the penis would be superior in my opinion. That is in a controlled way at 40 degrees or so.

Things like sauna, hot baths and warm clothes could affect your testicles for the worse. Another problem is that you can't really regulate the temperature and keep it at a constant level for too long.

Moreover, too much heat could potentially be harmful even to your penis. It's actually more of an unexplored territory so there's no telling what could happen.