What is a cold shower?

i herd of it in one tree hill

its a shower you take when you are turned on or had sex.

It's just that: a cold shower. When people get sexually turned on or whatnot, a lot of times they'll say "I need a cold shower" to cool off from the sexual tension and horniness... and all that jazz ;) LOL
A shower with cold water to cool down.
[Fred:] Like them idiots in Waco,
you're burning up in Bako where your father had your mother,
your mother had your brother, it's just too bad your father's mad,
your mother's now your lover.
[Jon:] Come on hillbilly, can your horse do a f.u.c.k.i.n' wheelie?
You love it down south, and boy, you sure do got a purdy mouth.