Possible effect on fertility by PKILLERH

A study by State University of New York researchers found that heat generated from laptops can raise the temperature of the user's lap when balancing the computer on one's lap, potentially putting sperm count at risk. The study, which included roughly two dozen men aged 21 to 35, found that the sitting position required to balance a laptop can raise scrotum temperature by as much as 2.1 °C (3.78 °F). However, further research is needed to determine whether this directly affects sterility in men.^[44]
A 2010 study of 29 males published in Fertility and Sterility found that males who kept their laptops in their laps experienced scrotal hyperthermia in which their scrotal temperatures increased by up to 2 C. The resulting heat increase, which could not be offset with a laptop cushion, may increase male infertility.^{[45][46][47][48][49]}
A common practical solution to this problem is to place the laptop on a table or desk, or to use a book or pillow between the body and the laptop. Another solution is to obtain a cooling unit for the laptop—These units are usually USB powered and consist of a hard thin plastic case housing 1, 2 or 3 cooling fans (with the entire assembly designed to sit under the laptop in question) which results in the laptop remaining cool to the touch, and greatly reduces laptop heat buildup.

[edit] Thighs

Heat from using a laptop on the lap can also cause skin discoloration on the thighs known as "toasted skin syndrome".^{[50][51][52][53]}