Modern day Laptops operate on very fast microprocessors that generate a lot of heat. This heat mainly escapes out of the bottom of the laptop but ventilation efficiency is reduced when the laptop is placed on a solid surface or on your lap and the ventilation holes get plugged. A hot laptop is less trustworthy and an overheated system is likely to fail.
Laptops work best at temperatures ranging from 95-104°F (35-40°!). When temperatures rise and reach between 104-122°F (40-50°!), there is twice the risk of a hard drive crash! Hard disk drives can overheat and crash, causing you to lose precious data!
Not only is a hot laptop unpleasant to use in your lap but also the heat from some laptops can be enough to cause superficial skin burns, right through your clothing! As reported in the Lancet medical journal a healthy 50-year old scientist, fully dressed in trousers and underpants, burned his genital area after placing his laptop on his lap for an hour. While using the laptop he did feel the temperature and a burning feeling on his lap and thighs. Two days later he had blisters that burst and developed into infected wounds.
Besides being uncomfortable to use, laptops can even reduce the fertility in case of males. Researchers have concluded that working with a laptop placed on the thighs raises the skin temperature significantly. This further exposes the groin area to higher temperatures. It is a known fact that long-term exposure to heat has a harmful effect on male fertility, as the testis are located externally. The sitting position required to balance a laptop can raise scrotum temperature by as much as 2.1 degrees Celsius. Heat from the laptop itself can raise the temperature by another 0.7 C, bringing the potential total increase to 2.8 C. European fertility studies, meanwhile, have shown that in general, an increase in scrotum temperature by 1 C can reduce sperm count by as much as 40 percent. A common practical solution to this problem is to place the laptop on a table or desk.
Thriving sales of laptops have also led to a surge in the number of computer users with back and muscle problems, experts have warned.
Not sitting in a chair with the computer at the right height is taking a toll and children as young as 12 are being diagnosed with nerve injuries caused by slouching over screens. Many others are at danger of damage to their spines, necks and shoulders because of poor posture when using laptops.
The problem is being magnified by falling prices and the ever-increasing availability of wireless technology, which makes portable computers more attractive. As such, Laptop sales are rising by leaps and bounds. Moreover, laptops not subject to the same health and safety regulations as desktop computers making them more prone to incorrect usage.
A common problem is perching a laptop on the legs so users stare down at the screen and put strain on their necks, spines and legs.
Back and neck pain is caused by using a laptop on the move, such as on a train. Resting wrists against the edge of a laptop cab easily induce hand and arm pain similar to repetitive strain injury. It stops the nerves and tendons moving as they normally would, and this can cause nerve injury.