 [ Symptoms ] can anxiety keep a man from being able to ejactulate or maintain an erection  my boyfriend knows that him not being able to ejaculate whenever we have sex makes me feel like it is because i am unattractive he was not sexually active for several years before i came along is it my fault in the sense of making him worry so badly about not being able to and upsetting me that he loses his erection altogether [ Disease ] sperm producing cells in the testicles are very heat sensitive which is why a human male is testicles are in the bottom of the scrotum when cold they pull in tight when hot they relax and pull away the thin wrinkled skin of the scrotum also allows for rapid heat dissipation like radiator fins on a car or air conditioning unit the type of underwear you wear makes no difference in many studies hot tubs are indeed bad for fertility but only for the few months after until you can make new sperm the sperm production cycle is 74 to 90 days long i tell my fertility and vasectomy reversal patients to avoid hot tubs hot baths jacuzzis or hot saunas