Ok so me and my husband recently found out from his sperm test that there were a few sperm found but they were all dead!! He had 2 older boys ages 19 and 15. Since his 15 year old was born he has been wearing polyester football shorts day and night constantly for 15 years instead of cotton boxer shorts! Could this really have killed all of his sperm? He has started to wear 100% cotton loose boxer shorts now and he is going to retake a sperm test in a few months to see if this has helped but I just wanted if this could be true as I've read online that polyester can lower sperm count due to the heat it causes and also the static that they cause....but could wearing them for so long kill them all? Not one was found alive in his sample and this is out last resort! Thank you in advance.