Researchers noted in a Fertility and Sterility journal that sitting for 90 minutes in a heated car seat may not be as luxurious as expected. Because sperm are dependent on a constant temperature lower than that of body temperature, direct heat from seat heaters may have long-term effects on male fertility.
Another study, from the ASRM (American Society for Reproductive Medicine), discussed the influence of a heated versus an unheated car seat on scrotal temperature. This study suggests that the frequent use of a heated car seat represents an additional scrotal, and consequently, testicular heat stress factor to that which is present by merely sitting for long periods.
“It is too early to (make) any conclusions concerning the influence of heating car seats on semen quality,” researchers told Reuters Health.
Another more recent comprehensive evaluation* (of relevant articles published between 1970 and 2017) cited “Hypogonadism and erectile dysfunction can be associated with sports with high rates of head injuries, such as American football. Although early reports linked other sports, such as bicycling, to erectile dysfunction, subsequent studies isolated these associations to sports cycling rather than recreational cycling. Certain sports (football, basketball, handball, and volleyball) were linked to increasing prevalence and severity of varicocele, offering a potential link to male infertility. In addition, recreational activities such as sauna, hot tubs, Jacuzzis, heated car seats, and laptop use were associated with high testicular temperature, which can impair spermatogenesis. Radio frequency electromagnetic waves from cell phones and laptops have also been shown to have deleterious effects on sperm viability and motility.”
*Source: European Urology Focus, 2018.