According to a study published by the State University of New York, using laptops on your lap might have an adverse effect on male reproductive health.
Urologist Yelim Sheynkin conducted the study by placing thermometers on the scrotums of 29 men using a laptop on their laps. Within 10 to 15 minutes, the men's scrotums overheated to dangerous levels without the users noticing.
"Millions and millions of men are using laptops now, especially those in the reproductive age range," said Sheynkin. He noted that users would not become infertile simply by using laptops, but that frequent use could add to existing problems because "the scrotum doesn't have time to cool down."
The obvious solution would be to take assume a different stance and spread the legs apart, but even this doesn't help much, as the testes will overheat in about 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," said Sheynkin.