If you are using any sort of lamp pointing it at the midshaft for tunica. I don't know much about the use of lamps, but when I use my heating pad, I usually target the area I am going to stretch , primarily, there's no such thing as isolation of the penil tissues, cause it's all connected.....Holla
The tunica surrounds the CC and CS. It runs the entire length of the penis. It is what keeps your penis from expanding too much when you get an erection. To warm it up, you have to warm the whole thing up. It is not like the ligs.