Basically,males in whom testes fail to descend to the scrotum are generally 'infertile' . Formation and development of sperms takes place in the testis .The high temperature is damaging to the sperms. The temperature in the human scrotum is usually lower (1.5 to 2.5 degree celsius ) than the normal body temperature (which is 37 degree celsiusĀ ) .In order to escape from the higher temperature of body , the testis descends into the scrotum .But theĀ males in whom testis do not descend remain infertile as the sperms can not survive at the higher temperature