Notebooks, Laptops and Hot Laps
Does a hot lap make a difference?
Yes, if it is your lap.
SUNY Stoney Brook researchers did a study to find out if laptop computers affected the temperature of the sperm in male users' reproductive organs. Hyperthermia is a recognized risk factor for male infertility. Their study found that 60 minutes with a laptop on the laps of 23 male volunteers did raise their lap temperature higher than sitting in the same position without a working laptop for the same amount of time. In their conclusion they wrote "Working LC in a laptop position causes significant ScT elevation as a result of heat exposure and posture-related effects."1
Of course, this do-it-yourself anti-fertility technique, although a potentially last ditch fall back for young males, is even more unreliable than the rhythm method, and should not be used as a form of birth control. Besides, it sounds quite uncomfortable.
Another group of researchers at the University of Connecticut Health Center looked into a case of lesions on the thighs of a woman. "After an extensive workup, she was diagnosed with erythema ab igne caused by laptop computer use." 2 It healed after three months without direct laptop on the lap use.
If you habitually do use a laptop on your lap, you may want to consider using either a laptop cooling pad or a laptop desk to keep the heat from reaching you. There are a number of different options which will keep you comfortable and free from suffering either issue.
1 Increase in scrotal temperature in laptop computer users; Sheynkin Y, Jung M, Yoo P, Schulsinger D, Komaroff E; Hum Reprod. 2005 Feb;20(2):452-5. Epub 2004 Dec 9.
2 Laptop computer--associated erythema ab igne; Levinbook WS, Mallett J, Grant-Kels JM; Cutis. 2007 Oct;80(4):319-20