http://www.timesonline.co.uk/article/0,,2-1395183,00.html By Sam Lister Scientists have linked portable computers and male infertility BUSINESSMEN and teenage boys could be risking their fertility by using laptop computers, research suggests. The combination of heat generated by the computers and the posture needed to balance the equipment on the lap leads to raised temperatures around the scrotum, a study has found. Past research shows that higher scrotal temperatures can damage sperm and affect fertility. And the introduction of new technology such as Bluetooth and infrared connections which provide wireless links to the internet has resulted in a growing number of men using the machines on their thighs rather than at a desk. To keep the testicles at an ideal temperature and for greater comfort men naturally sit with their legs further apart than women. When working on a laptop, however, they will adopt a less natural position in order to balance it on their laps, which results in a significant rise in body heat between their thighs. The latest findings, published in the journal Human Reproduction, give warning that teenagers and young men should consider cutting the time spent with a computer positioned on their lap because of the possible long-term damage to their fertility. Researchers from the State University of New York said their study was the first to look at the effect of heat from laptop computers on scrotal temperature. Using 29 volunteers aged 21 to 35, the researchers, led by Yefim Sheynkin, found that sitting with the thighs together to balance a laptop caused scrotal temperatures to rise by 2.1C. But when the laptop was in use, average temperatures rose by 2.6C on the left of the scrotum and 2.8C on the right. The body needs to maintain a proper testicular temperature for normal sperm production and development, Dr Sheynkin said. Portable computers in a laptop position produce scrotal hyperthermia by both the direct heating effect of the computer and the sitting position necessary to balance the computer.