I always take cold showers anyways because I don't feel as clean after a hot shower . I think it's cause I sweat so much. I dunno if it would good around Penis Enlargement because the cold does cause some shirnkage. You could just use a hetaing pad I guess.
I'm sure i'll be corrected if i am wrong, but no taking a hot shower wouldnt. Just becasue the opposite causes an increase doesnt mean this would cause the opposite of it. Lying in the sun or in a jacuzzi wouldnt cause your body to decrease it either (so do lots of them )
The cold water i believe causes the body to scream "wtf!!" as if its under attack and go into a defensive response mode that includes extra testosterone.
Shitloads of stuff causes it, bad diet, old age, testicular injuries etc. But basically nothing that you would come across in everyday life. Your testosterone level is kinda at its natural level and it would take something very big and blatant to affect it, so you'd know it had occurred and what had caused it.
If you are worried about your testosterone level there are various threads around here on how to increase it naturally, usually by one of the Penis Enlargement pros.
Decided to get off my arse and answer my own Q;
"Why does stress cause a man's sperm count to plummet? Research led by Population Council endocrinologist Matthew Hardy found stress hormones overpower the enzymes responsible for ensuring cells in the testes produce testosterone, which is necessary for sperm formation. "
Quite surprised by this, i guess you do learn something every day