We've long known about the alleged connection between hot notebooks and male fertility problems, but according to a new study, even a cooling pad won't solve the problem. In a study entitled "Protection from scrotal hyperthermia in laptop computer users," State University of New York at Stony Brook Urologist Dr. Yefim Sheynkin and his associates measured the scrotal temperatures of 29 young men while they were using notebook computers on their laps. The results: scrotal temperature increased quickly and dramatically even when the men used lap desks.
Apparently, the cross-legged position, rather than the ambient heat of the device itself, is to blame. After only an hour using notebooks on their laps, the mens' testicle temperatures had risen a dangerous 2.5 degrees Celsius.
"Within 10 or 15 minutes their scrotal temperature is already above what we consider safe, but they don't feel it," Sheynkin told Reuters Health.
The men's sperm count was not measured nor was their fertility tested. However, it's well known that even a 1-degree rise in scrotal temperature is enough to kill sperm.
“Sperm formation and sperm production needs to be at a lower body temperature than even our core body temperature and that’s why the testicals are outside of the body so if you heat up the body, it can negatively impact sperm production and formation," Suzanne Kavic, Loyola University' s director of reproductive endocrinology and infertility, told us in an earlier interview.
The study also showed that users who sat with their legs further apart had better results, but even they saw scrotal temperatures rise after just 30 minutes. "No matter what you do, even with the legs spread wide apart, the temperature is still going to be higher than what we call safe," Sheynkin told Reuters.
At this point, it's unclear how long a man would have to use a notebook on his lap to see a measurable decrease in viable sperm count. Kavic told us that it takes sperm 72 to 74 days to become functional so your notebook use today may not affect you for almost three months. And nobody has done a longitudinal study to see what happens at that point.
The best advice, Kovic said, is to limit the amount of time you put your PC between your legs. "I don’t tell them not to use notebooks," she said of her patients. "I do tell them to try to limit it, to be aware of it."