There's more - apparently, the effect wasn't so bad when the men kept their legs spread wide apart. Also, laptop cooling pads like these are apparently not a guarantee to protect damage to your quick-swimmers. So, what can one do to prevent this? If you heavily use the laptop on well, your lap, then you could take these preventative measures:
1) Use it on a desk whenever possible - Not only will this let the heat not affect the sperm, but by keeping it on a desk with the screen facing parallel to your eyes, it will also help to improve your sitting posture. We'd especially advise this while using applications that are intensive on the CPU or the graphics chip (think 3D Studio Max or encoding videos), which are the main culprits that make your laptop heat up more than usual in the first place.
2) Do not charge while using it on the lap - It is an observed fact that laptops tend to heat up while charging.
3) Take a break - Give your heating thighs a much-deserved rest by not continuously using the laptop on the lap for hours. We'd say take a break for a couple of minutes every hour.
4) Use a smartphone - If there are tasks (like responding to e-mails) that can be accomplished via your phone, then you could might as well use a smartphone to do them instead of opening up your laptop.