A study by urologists from the State University of New York at Sony Brook warns that using a laptop cooler is no guarantee to prevent male infertility problems when using a laptop directly on your lap:
In a study published today in Fertility and Sterility, a group of urologists from the State University of New York at Stony Brook monitored the scrotal temperatures of 29 young men on their laptops, both with and without a cooling laptop pad. Some sat with their knees closed, others with their legs open at a 70-degree angle.
All the subjects experienced an increase in their scrotal temperatures by 1.41°C-2.31°C, though the group using a laptop pad and sitting with their legs open experienced the smallest temperature change. Sounds insignificant, but even a 1-2°C raise in temperature can damage sperm and increase the risks of infertility.
"Within 10 or 15 minutes their scrotal temperature is already above what we consider safe, but they don't feel it," Dr. Yefim Sheynkin told Reuters.