Does the heat from a laptop affect fertility?

Perhaps: Excessive heat is not a good thing for eggs and sperm. However it takes a lot to heat them up and a laptop does not generate enough heat under normal circumstances to raise your core body temperature. Immersing your ovaries or your testicles in hot water can raise the temperature enough to cause harm - so jacuzzis are out.

Other issues?: The issue with laptops is not heat but perhaps radiation. The jury is still out but there are some concerns about excessive exposure to radiation from devices such as cell phones and laptops. At this point, it is probably best to minimize exposure to protect yourself from radiation.