Sperms are produced in the testes by spermatocytes through a process called spermatogenesis under the influence of DihydroTesterone. Exact location of spermatogenesis is germinal epithelium leydig cells of testes. Every Germ Cell (Sperms & Eggs) has a specific temperature requirement for incubation. Below or above that temperature it does not survive. That is why testes are located inside scrotum. The internal temperature of scrotum is usually 2 degree less than body temperature. To maintain this, the scrotum along with testes stick to body during cold and go away in hot condition.
